Fish Health Management Fundamentals and Treatments for Common Fish Diseases

Healthy Koi Fish

If you are going to own fish, whether, in your garden pond or an aquarium, you should really know a few things about fish health. You can surely hire someone to clean your garden pond or maintain your aquarium, but it will pay to learn about the fundamentals of fish health management. The fact that you are still reading this article would indicate to me that you might just have a few fishy friends.

Now, if you’re wondering, “Does this guide apply to recirculating aquaculture systems, as well?” Yes, it does! The majority of the information I’ll share here can also be used in maintaining edible fish species, but to be clear, I will be focusing on koi and goldfish instead of most commercially farmed fish species like catfish or tilapia.

What is Fish Health Management?

Fish health management encompasses different practices meant to prevent various fish diseases. This is essential to large commercial fish farming industries and maintaining fish health in garden ponds and aquariums.

Three of the most critical areas of fish health management are water quality, fish nutrition, and sanitation. These are the common sources of fish stress that should be controlled to maintain a thriving pond or tank setup. The following section takes a closer look at these three areas.

Fundamentals of Fish Health Management

The fundamentals of fish health management mainly focus on prevention. This idea is that it is better to avoid certain conditions that could lead to fish diseases than deal with the repercussions later on.

1. Water Quality Management

Providing a healthy environment for your koi and goldfish begins by giving them quality water to live in. In an indoor aquarium, you will likely want to monitor temperature, dissolved oxygen levels, pH, general hardiness, alkalinity, ammonia, nitrate, nitrite, chlorine, and chloramine levels, while a well-balanced ecosystem pond should take care of all of these levels for you.

It is important to remember that the further we stray from nature, the harder we make things for ourselves and our fish. The fish are very far removed from their natural environment in an aquarium, so we need to monitor things closely. In a naturally balanced pond, mother nature does all of the heavy lifting, and we just need to be careful not to upset the balance too much.

Below is a detailed discussion on monitoring each aspect according to the needs of your koi and goldfish:


Your pond or aquarium’s water temperature is crucial to the health of your fish. The hotter the water, the more the toxicity may increase and the less oxygen it will hold. Because they are cold-blooded, fish’s metabolism is directly tied to water temperature.

The ideal water temperature of a goldfish or koi pond is between 59° and 77° Fahrenheit, but the temperatures can stray far outside these guidelines with adequate aeration. Goldfish and koi can withstand very hot and cold water, but they cannot withstand quick temperature changes. This is why when moving any fish from one body of water to the next, we need to ensure that the temperatures closely match. Whenever I move fish from one pond to another or from our fish holding tanks to a pond, I check the temperature of the water with my hand. If I can’t tell the difference between the water temperatures with my hand, the goldfish and koi will be fine with the temperature.

Meanwhile, most experts suggest keeping your koi at 65° and 75° Fahrenheit for aquarium environments.

Dissolved Oxygen

Oxygen levels in a pond or aquarium significantly impact fish health. As stated before, hotter water holds less oxygen, while cooler water holds more.

Depleted dissolved oxygen (DO) is one of the major causes of fish kills in aquariums and ponds. Some of the primary sources of low DO are atmospheric conditions, high water temperatures, harmful algal blooms, chemical treatments, stratification, and pond turnover.

Bottom aeration systems can be installed to supplement the amount of DO in your pond or aquarium. These systems have an air pump that pumps air through tubing to the bottom of the body of water, where the air is pushed through an air stone or diaphragm diffuser causing many tiny bubbles which rise to the surface of the water. This process adds oxygen to the water and circulates the water.

Another way to increase oxygen levels in your pond is to install a waterfall or a fountain pump. Any time that water is falling and splashing, it introduces more oxygen into the water.

For koi and goldfish, the minimum oxygen level required is 6.0 mg/L. However, a higher concentration facilitates healthy growth, reproduction, and tissue repair.


One thing you should monitor in your aquarium is the pH or the level of acidity of water. If you’re not familiar with pH, it has a 0-14 scale, with one as the most acidic and 14 as the most alkaline.

To keep your koi and goldfish in good shape, ensure that your water has a stable pH between 7.0 and 8.6. Anything under or over the range may be detrimental to your pet fish.

Specifically, pond or aquarium water with a pH higher than 8.6 may lead to Alkalosis, a condition that occurs when water is too basic for the fish to tolerate. Likewise, any pH lower than 7.0, which leans toward acidity, may result in Acidosis. In worst-case scenarios, both Alkalosis and Acidosis may lead to fish kill.

I have been keeping koi and goldfish ponds for many years, and I have not found a need to monitor the pH levels of pond water. I maintain many ponds, and the fish do just fine. This is another case of nature taking care of the balance.

General Hardness

Different minerals are found in water, such as calcium, magnesium, borate, iron, and silica. General hardness or water hardness is used to describe the concentration of this mineral content in water.

The rule among fish enthusiasts is that the harder the water, the better fish health. Usually, this hardness comes from calcium and magnesium.

Unlike the pH level, water hardness is not that critical. However, it is best to keep it to a 60 to 160 ppm range.

I do not monitor hardness in any of our Wisconsin ponds and have never had an issue.


Another thing you should monitor, especially concerning pH, is alkalinity or also referred to as carbonate hardness (KH). It determines the amount of carbonates (CO3) and bicarbonates (HCO3) in your aquarium water.

Why is KH important? Simple, KH protects the water’s pH level from fluctuations. Having a high KH level is beneficial because it neutralizes acid, affecting pH levels.

Keeping your KH at around 105 ppm is best to avoid pH fluctuations and stabilize its pH level.

We do not monitor KH in any of our ponds.


Ammonia is one pollutant to look out for as it is toxic for your koi and goldfish. There are different sources of ammonia in ponds, the primary source being your fish, as they naturally excrete ammonia when they breathe, urinate, and defecate. Debris, such as uneaten fish food, also creates ammonia. A pond with poor circulation and filtration that is heavily loaded with fish can certainly develop high ammonia levels. But, with average fish loads, good circulation, and plenty of plants, this is never a problem in our naturally balanced ponds.

This substance is potent as even a little bit may cause so much damage to any fish. When left unaddressed, ammonia can burn your fish’s gills, preventing it from getting dissolved oxygen from the water.

Ideally, it is best to have no ammonia, so maintenance of water quality is critical. If your ammonia level already reaches 0.25 ppm, know that it’s a cause for alarm, and you should take the necessary steps to address the problem.

Nitrite and Nitrate

Nitrites and nitrates are closely associated with ammonia and are equally significant in your pond’s ecosystem. Good bacteria turn ammonia into nitrites which are then converted into nitrates. One benefit of having plants in your pond environment is that they eliminate nitrates.

An abundance of nitrites can result in fish kidney and nervous system problems. Similarly, too many nitrates can lead to immune system problems.

A reading of 20 to 60 ppm is okay for nitrates, while nitrites should be less than 0.25 and, if possible, go down to zero.

In a naturally balanced ecosystem pond, you won’t have this problem either, since nature’s balance takes care of any levels that get out of balance.

Chlorine and Chloramine

Chlorine and chloramine are very harmful substances that can lead to fish kill, and they do so by damaging gills and scales, which later leads to breathing difficulties. This is why it’s essential to always use chlorine and chloramine remover whenever you add city water to your pond.

Both of these chemicals are used in treating our drinking water as these two eliminate bacteria, parasites, and bad odor, making water potable. While water with a certain amount of chlorine is safe for humans, it is most definitely not for fish. Aside from damaging the insides of your fish, chlorine gets rid of bacteria, including the good ones that reduce ammonia and nitrites. If you are lucky enough to get your water from a natural well that is not chemically treated, then you don’t need to worry about these chemicals.

One fact about chlorine is that it can evaporate. On the other hand, chloramine is harder to deal with as it is a mix of chlorine and ammonia. As I mentioned earlier, ammonia is definitely something you wish to avoid in fish ponds. The ideal level of chlorine and chloramine in pond water is none or 0.00 ppm as these do no good at all.


Algae is a natural part of all ecosystem ponds, but we can get extreme algae blooms when things get way out of balance. These will typically occur when we get a rich nutrient source entering our ponds, such as chemical fertilizers or animal manures. In these cases, ponds can be overloaded, and low oxygen levels can result.

While it is possible to have low oxygen levels with extreme algae coverage, fish kills are most common when people try to kill the algae with chemical treatments. Killing large quantities of plants of any sort in a pond will cause oxygen levels to crash and can easily result in fish kills.

2. Fish Nutrition

The nutrition you provide to your koi and goldfish is almost as important as water quality. Both species are omnivorous, so they eat whatever is given to them.

There are three types of food when it comes to fish feeding:

  • Natural food includes creatures naturally found in ponds such as bacteria, plankton, insects, fish, and aquatic plants.
  • Supplementary feeds are relatively cheap items such as kitchen waste, terrestrial plants, and agricultural byproducts.
  • Complete feeds are usually packed with nutrients and are easy for fish to eat and digest.

In a natural pond setting, koi and goldfish eat algae and can survive without supplemental feeding. On the other hand, if they are placed in a more controlled environment, you may have to give them the nutrition they need because of the lack of natural food. I always tell people that if they have their pond and fish to have a really clean pond, then don’t feed the fish. On the other hand, if the reason for the pond is to raise big, colorful fish, then feed them because they will grow more quickly and be more colorful.

As they feed on animal and plant products, you can also explore giving them food other than processed feeds. Insects, small fish, and other aquatic animals can be added to their diet, giving them the illusion of a natural setting. Among these are worms like silkworms, earthworms, mealworms, shrimp, tadpoles, and larvae of wax moths and mosquitoes.

Fruits and vegetables are also good sources of vitamins and fiber. Lettuce, watermelon, oranges, broccoli, carrots, pineapple, and apples are just a few of the many natural foods they will eat.

3. Sanitation

Just like humans, fish need a clean environment to be able to thrive. From my experience, an aquarium needs regular cleaning and water changes simply because it’s a clear plastic or glass box inside the home. On the other hand, Ponds can be almost maintenance-free if built correctly with wet well intakes and wetland filters.

Giving your pond the proper circulation, filtration, bacteria, and plants will be all that is needed for a very easy care pond.

Even with a well-balanced, natural pond, we should monitor the pond bottom to ensure that large accumulations of debris are eliminated as needed. With good balance, these debris piles will be minimal, but in yards with heavy tree cover, the pond water will collect more leaves than it can naturally digest, so some manual leaf removal will be necessary.

Fish Diseases

1. Causes of Koi and Goldfish Diseases

Koi and goldfish are not insusceptible to diseases. In fact, there are diseases these species commonly face, which every pond owner should know.

Awareness and knowledge of these health risks will help owners address them early on. The saying prevention is better than cure rings true, and preventing these issues is easier than remedying them later.

Pond owners should watch for several common causes of koi and goldfish diseases.

Improper Feeding

Diet is of utmost importance when caring for your koi and goldfish. Improper feeding, which covers not giving the proper diet and overfeeding, is one common cause of health problems.

Nutritional diseases arise when your fish does not receive the dietary requirements for optimum health. In selecting food that you give your pet fish, you should consider the nutrients it offers to ensure that nutritional needs are met.

Aside from the quality of food, one thing to consider is feeding frequency. While watching your koi and goldfish eat is enjoyable, you should be careful not to overfeed. It is more common for owners to overfeed their fish than underfeed.

How often should you feed your koi and goldfish? The rule of thumb among koi and goldfish enthusiasts is to feed only once a day.

Your next question would probably be: how much should I feed my koi and goldfish? This can be tricky as there is no one-size-fits-all solution in fish feeding. In general, the fish should quickly eat any food that hits the water. If you toss food onto the water and some remains, your fish are definitely overfed.

Never feed your fish when the water temperature drops below 50 degrees Fahrenheit. At this temperature, their metabolism slows, and this can cause food to go undigested and rot in their bellies.


When subjected to stress, fish can experience a decline in health. If you notice listlessness in your koi and goldfish, you may have overlooked some conditions that have caused this stress.

Different situations can trigger stress, such as rough handling, predators, and overcrowding in the pond are some of the most common causes in a naturally balanced pond.

Attack by Disease Organisms

External factors such as disease organisms also cause illnesses among fish. These organisms attack fish externally or internally, and external problems affect skin, gills, or fins, while internal problems affect the blood, nervous system, digestive tract, and the like.

Living organisms that pose health risks may be classified into three: viruses, bacteria, and parasites. Both viruses and bacteria are not visible to the naked eye and can be detected through tests and laboratory techniques.

Parasites, to some extent, can be seen and may be present inside or outside of the body. Organisms that dwell in the body of your fish include sucking worms and tapeworms, to name a few. Meanwhile, leeches, flukes, fish lice, water fungi, protozoa, and copepods live outside the body or just within the pond environment.

Luckily, with proper treatment and early detection, you can remedy the diseases caused by these organisms.

2. Areas to Analyze for Fish Diseases

Think something is wrong with your koi and goldfish? This checklist will guide you in determining if your fish is experiencing a health issue. By knowing which areas to check, you can narrow down possible problems your fish may face.


Fish waste is among the things you should check to know what is wrong with your koi and goldfish. The normal waste of koi and goldfish is brown and would sink to the bottom and dissolve. If it is gelatinous in consistency and floats, there may be an issue in your fish’s digestive system.

One problem that manifests in feces or waste is your fish’s diet. Double-check the quality and kind of food you give your koi and goldfish. Further, you can check for debris that may have fallen into the pond that caused this.

Physical Body

You can often see physical signs of disease on your fish.

Some alarming issues are the presence of opaque mucus on the body, wormhole-like things on the scales, and tiny parasites. Having a microscope at home will come in handy because you get to see minuscule features and organisms.

Take a look at your fish’s scales to see if there are noticeable differences from the usual. Red spots or congestion on the gills, skin, and mouth are also signs of health issues such as bleeding.

After a visual check, use your sense of touch for further findings. Feel your pet fish’s body and note if it is slippery as it naturally should be. Dryness can be a symptom of diseases such as gyrodactylus and chilodonella.

Take note of any unusual findings in the eyes, abdomen, gills, and other parts.

The eyes are the windows to the soul, but they also tell you if there is a problem. Check if the eyes are popping out or sunken in, look clouded, or seem like they are rotting.

For the abdomen, see if parts look swollen or bloated. Also, look for redness around the mouth or gills, as this may be a tell-tale sign of breathing difficulties. Aside from redness, check mucus or secretions around the gills that are white, grey, or yellowish. Note that when breathing, the gills of a healthy fish will have an open-and-close pattern and be deep pink in color and not pale or white.

Death Patterns

For the most part, in a well-balanced outdoor pond, we don’t see much of any of the above-listed illnesses. I can tell you that when we sold fish and held them in properly circulated indoor tanks, the number of sick fish made it very difficult.

In our natural outdoor ponds, the fish are at risk from predators such as the Great Blue Heron and Mink, but not so much from disease.

We will lose some fish over winter. Here in Wisconsin, we keep bottom aerators running over the winter months, and our ponds are frozen over with ice from December through March. We do typically see a few dead fish in spring, but it is not clear why they died.

I can say that here in Wisconsin; I have seen situations where fish begin to die several weeks after the ice melts. I think this is because the pond owner has not yet started the pond filtration and circulation system, and maybe the water is too still? We always recommend getting the pond running as soon as possible, and if not possible, we would recommend a partial water change to get the fish some new freshwater. If you are doing a partial water change, make sure to add a dechlorinator if you are on city water.  

It is unfortunate when one of your pet fish dies and all the more when you lose more than one. If death should occur, you should take note of the details and circumstances which may help you prevent further damage to your pond.

A common cause of fish disease in our natural ponds is the addition of new fish from a fish retailer. Any time you introduce new fish into your pond, you risk introducing disease. Always remember to do proper quarantine. Keep your koi or goldfish in an isolated or separate tank or pond for two to six weeks. This will give you time to spot bacterial or parasite infections that are both common causes of illness and, eventually, fish kill. By doing so, you are protecting your existing pond.

Another cause of fish kill is the ingestion of poisonous substances. Suspicious debris floating or at the bottom of the pond, strong-smelling chemicals, and other unnatural substances are signs to look out for as these may have led to the poisoning of your fish. If you hire a pest control company to spray for pests in your yard, these same chemicals can easily kill your fish if they get in the water.

Should you not be able to determine changes or actions done that may have caused the unfortunate death of your koi and goldfish, check and evaluate the bodies of the ones that passed away to find out what went wrong.

3. Common Fish Diseases and Treatment

Knowledge is definitely power. Knowing the diseases that commonly plague koi and goldfish will help you detect problems and find remedies early. In general, your best defense is a well-balanced, healthy pond. While sick fish can be treated with medications, it is very difficult or even impossible to do in a pond. If you see a sick fish in your pond, I suggest removing it immediately and putting it in a separate container. This way, you can easily medicate it if you choose to do so, and it is not getting your other fish sick if the disease is easily passed from fish to fish.


  • Causes: Dropsy is a problem that koi and goldfish commonly encounter. There are several known causes for Dropsy. It may be caused by a bacterial infection hitting the kidney or liver with the bloodstream as the route of infection. It may also be brought by the Mitraspora cyprini, a rare fish parasite that hits the kidney.
  • Symptoms: Physical signs to look out for that point to Dropsy are raised scales that resemble a pine cone, bulging eyes, fluid retention or body swelling, and loss of balance. Internal symptoms include congenital heart or kidney failure, kidney enlargement, and the loss of function for the organ.
  • Treatment: Dropsy isn’t contagious, and treatment is dependent on the nature of the problem. Since there is a wide range of possible causes with similar symptoms, the best action plan is to give varied treatments. There are medications for Dropsy that are antibacterial, antibiotic, and antiparasitic.


  • Causes: Flukes are parasites among the most common to hit koi and goldfish. These parasites attach themselves to either the body or gills of fish and may hit the entire pond when left unaddressed.
  • Symptoms: Tell-tale signs of fluke infestation are flashing where fish scratch themselves against other objects or the bottom of the pond, frayed fins, difficulty breathing or frequent gasping, excessive mucus secretion, and weight loss.
  • Treatment: To treat flukes, koi are given Supaverm of Potassium Permanganate, while goldfish are given Praziquantel or Potassium Permanganate. Immediate treatment of the affected fish is vital not to affect others in the same pond.

Fin Rot

  • Causes: Much like Dropsy, fin rot is a condition that comes with another underlying problem. When under stress, koi and goldfish become more vulnerable to bacteria, leading to fin rot. Fins start to rot when the immune system is weakened due to poor water quality, disease, fin nipping, temperature change, and overcrowding, among others.
  • Symptoms: Aside from apparent rotting of the edges of the fins, fin rot can also have symptoms like fin discoloration, missing fins, inflammation near the fins, and behavior change like hiding and rubbing. If the condition worsens, fins will completely deteriorate up to the body tissue.
  • Treatment: Since poor living conditions contribute to fin rot, be sure to test and address problems to bring back water quality. Once the pond water is safe again for your koi and goldfish to live in, you can already start treatment using antibacterial medication.

Gill Rot

  • Causes: Gill rot, also known as Columnaris disease, is caused by the Flexibacter columnaris bacteria. Columnaris is a serious and alarming skin and gill disease mainly affecting freshwater fish.
  • Symptoms: You will know it is gill rot or Columnaris when there is the presence of white and yellow mucoid patches all over the body. These are usually composed of swarms of the bacterium with a reddish hemorrhagic zone and necrosis surrounding it. The overall appearance makes the fish look like it is covered in white rags.
  • Treatment: Antibiotics and certain chemicals are used to treat external infections caused by Columnaris. Copper sulfate, Acriflavine, Furan, and Terramycin are added to water to help cure this condition.

Anchor Worm

  • Causes: Contrary to its name, anchor worm is not a specific type of worm but rather the Lernaea copepod crustacean. This typically occurs when new goldfish and koi are added to the pond that have not been quarantined.
  • Symptoms: Anchor worms, usually appearing as a short piece of thread hiding beneath a scale, may dwell unnoticed in the newly added fish and affect others. They are typically found in the affected fish’s oral cavity, making its mouth resemble baleen. Those that fall off leave behind patches of hemorrhage or fibrosis.
  • Treatment: Because the naked eye can see these string-like organisms, you may want to pull them out. The best action to take is to leave it as it is highly recommended to have it removed by a veterinarian while the fish is sedated. Bacterial infections may develop in the areas where these anchor worms attach, so monitoring is important. This can also be treated with organophosphates or diflubenzuron (dimilin) but with caution.


  • Causes: Fungus may grow and hit those with a weakened immune system when pond water quality is poor. Fish with existing infections and wounds are more likely to get fungal infections secondary to their condition.
  • Symptoms: If you find growths along your pet fish’s body and fins that look like cotton wool, it most likely has a fungal infection. When not treated immediately, fungal infections can lead to fatal results.
  • Treatment: Though it is not contagious, it is recommended for pond owners to isolate infected fish while it is being treated. Slowly take out the fungus with a cotton swab and use prescribed fungicide on the affected area. Infected fish should be monitored to avoid further infections. For the pond, improve water quality and at the same time use Methylene Blue to help get rid of the fungus.

Fish Lice

  • Causes: Fish lice or Argulus is quite common in koi and goldfish ponds. It may appear as green algae that has stuck itself onto the fish, but a closer look will show that it’s actually a tiny crustacean with a greenish-brown disk-shaped body. You can spot them in the stomach, throat, and bases of fins.
  • Symptoms: Fish lice attach to your fish, create tiny holes in the body, and leave red spots. With the fish lice attached, affected fish will try to scrape the organism off. If you notice abnormal activity like this, you may want to check for fish lice. Lethargy or less energy is also a sign, especially if the fish lice has attached itself long enough to make the fish anemic.
  • Treatment: Chemical treatment, such as Dimilin, is needed to eliminate fish lice and eggs in your pond. Be sure to read instructions carefully before doing these treatments to avoid harmful effects on your pond ecosystem. There are also recommendations from pond owners to use tweezers in removing fish lice with precaution.


  • Causes: Another parasite to look out for in koi and goldfish ponds is trichodina. It is pretty easy to identify this parasite with its wagon wheel-like appearance.
  • Symptoms: To know if a trichodina has latched itself to your fish, check if there is a gray film or mucus all over your fish’s body. Breathing problems may arise, especially when its effect has become severe. Other signs to watch out for are lethargy and flashing.
  • Treatment: The earlier the treatment of trichodina infection, the faster it will be, especially when it’s still in the early stages. Medication can be Potassium Permanganate or salt dip.


  • Causes: As with other bacterial infections, fish with a weak immune system are prone to getting ulcers. Ulcers are also caused by parasites such as flukes and anchor worms, so keeping your pond parasite-free helps prevent ulcers.
  • Symptoms: Initially starting as tiny red or white pimple-like spots, ulcers eventually become large holes that, when left untreated, will affect the muscle of your fish.
  • Treatment: Fish suffering from ulcers need medicated food to help them recover. Bath treatments of Tricide-Neo, antibiotic injections, and antibiotic ponds are courses of treatment you can take for your fish.


  • Causes: Chilodonella are microscopic parasites that use their fish host as an anchor point in feeding off bacteria and microbes. These parasites stick to gills, especially in their juvenile stages. As these grow, they move to different parts of the skin.
  • Symptoms: Cloudy white spots on fish skin, flashing behavior, gasping for air, increased mucus production, clamped fins, and low energy are some signs that tell if your fish has a Chilodonella infection.
  • Treatment: One thing to remember in treating parasite and bacterial infections is that improving water quality does wonders in preventing further damage and recurrence. For fish with Chilodonella, isolate it into another tank and give necessary treatment such as a salt bath, salt dip, or Potassium Permanganate.


  • Causes: Very similar to the Chilodonella, Costia is a parasite that needs a microscope to be seen. This parasite attacks fish skin and gills and affects those with existing problems. It dwells more in colder water and is not that harmful unless it grows in large quantities.
  • Symptoms: Fish with less appetite and energy, fleshing, and extra slime production may be affected by Costia. Also, expect breathing problems, especially when gills are affected.
  • Treatment: Like other infections, keeping your affected fish in quarantine is the first step you should take. This prevents further damage to your pond and controls the situation. Costia may be difficult to treat once it has become widespread. Treatment includes medicated baths for the affected fish.

White Spot Disease

  • Causes: White spot disease is a common health problem that fish of different species experience. The sole cause of this problem is the protozoan Ich that sticks itself to fish’s gills. After clinging onto its host for about three weeks, the Ich will release its hold and settle at the bottom of the pond for reproduction.
  • Symptoms: You can identify it as white spot disease when there are small white spots on your fish that are the size of coarse sand or salt. However, other symptoms may manifest even before the appearance of white spots. These include lethargy, loss of appetite, and consistent rubbing of oneself against other objects.
  • Treatment: It is interesting to note that salt is a known medication for Ich. The salt concentration of the pond or quarantine tank is increased to about 0.5% for 10-21 days. For better and faster results, it is recommended to increase water temperature gradually. Another course of treatment is using malachite green and formalin, which requires caution and works best for short quarantine treatments.

Swim Bladder Disease

  • Causes: Swim bladder disease is when the fish cannot regulate its buoyancy. There are two types. First, the Positive Buoyancy Disorder is caused by either a change in diet, parasites, or a shift in the swim bladder. Second, the Negative Buoyancy Disorder is caused by many internal factors such as a rupture or infection.
  • Symptoms: You can identify the first type, Positive Buoyancy Disorder, when your fish floats at the top of the pond or on its side. On the other hand, with the Negative Buoyancy Disorder, your fish struggles to get to the top and stays at the bottom instead. This may go unnoticed because fish staying too low is not as noticeable as those that float too high.
  • Treatment: Different types and causes require different treatments. For Positive Buoyancy Disorder, if the cause is the diet, one possible remedy is to halt feeding for a couple of days to release excess gas. Surgeries to remove tumors and the like may also happen when advised by the veterinarian. Different plans may arise for the Negative Buoyancy Disorder depending on the diagnosis. While waiting for your veterinarian’s advice, you can help your affected fish by making it comfortable with the pond layout and giving it attention during feeding.

Gold Dust Disease

  • Causes: Also referred to as Velvet and Rust, Gold Dust disease is a common condition among freshwater fish caused by Oödinium or Piscinoodinium. There have been debates about whether it is a protozoan or algae because of its chlorophyll component.
  • Symptoms: As this is a parasite, infected fish will try to scratch the organism off its body. Other than flashing, symptoms for Gold Dust disease include lethargy, weight loss, labored breathing, clamped fins, and a velvety film of the skin that is either fine yellow or rusty. During its advanced stages, fish skin may start to peel off.
  • Treatment: This disease is contagious, so it is essential to remedy it at the soonest possible time. Treatment for Gold Dust disease includes raising the water temperature, dimming lights for several days, adding aquarium salt, and treating the pond with copper sulfate for ten days.

Final Thoughts

Starting a pond or aquarium is no easy task. There are a lot of things to consider. When your tank is unnatural and indoors, you have a much more challenging task as the tank will require you to care for it in the absence of nature. If you create a naturally balanced outdoor pond, most of the hard work is taken care of by nature, including fish health management. As the owner, you must be equipped with the proper knowledge of the fundamentals of caring for your pet fish and know-how on dealing with problems such as diseases that you may encounter later on.

I hope this guide provided you with all you need to know before you start your journey in building your pond or aquarium. Be sure to keep this in your bookmarks tab for when you need a quick reference as you explore the wonderful world of aquatics.

Waterfall and Stream Construction

Stream and Waterfall

Waterfalls and streams are very different water features, but they have more in common than differences. These are the magic parts of a water feature, and these are where the water comes to life to delight us and any other animals that live nearby.

The construction of both is similar but not quite the same, and their reasons for being are similar but not quite the same. These are often the most difficult, time-consuming, and creative parts of building a water feature. This article will give you some tips so that if you decide that you need a waterfall or stream, you will know the difference and know which you want.

This article assumes that you already have a pond of some sort.

Why Should I Build a Stream or Waterfall?

Ponds are wonderful ecosystems filled with life. One of the key ingredients to having a naturally balanced ecosystem is water circulation. In nature, larger bodies of water are circulated by animal movements, wave action, springs, and runoff water entering.

Backyard ponds are often too small to get much wave action and often don’t have springs or any watering entering them. This all too often leaves them somewhat stagnant. The addition of a stream or waterfall can give them the water circulation that they need to balance themselves out and improve water quality.

Waterfalls and streams also give us the added benefits of the sights and sounds of splashing and running water. Nothing attracts animals (humans included) quite like running water.  

The Similarities and Differences Between Streams and Waterfalls


  • Both need flowing water
  • Both need some grade change so that the water will run downhill.
  • Both will be lined with some type of liner. Typically rubber, but it could be any number of waterproof, flexible liners.
  • Both will be lined with rocks and river gravel to make them look natural and to protect the liner.
  • Both will have water pumped into the end furthest from the pond so that it will flow back into the pond.


  • A waterfall will typically have cascades or drops in level so that the water drops down levels.
  • A stream will be relatively flat and will usually twist and turn to give the moving water some interest.

Basic Materials Required for both Waterfall and Stream Construction:

  • Water pump
  • Pond Liner
  • PVC Glue
  • Decorative Rocks
  • Piping
  • Connectors
  • Pond Gravel
  • Underlayment Fabric
  • Pond Foam
  • Dual-Walled Plastic Culvert

Waterfall or Stream Construction

Building a waterfall or stream onto your backyard pond is not a very technical or difficult task, but it does take some practice and creativity to become really good at it. Many people will build several of them before they feel confident in their abilities. I’ll take you through the steps you can take to build your own.

First, there are some rules that you must keep in mind:

  • Water always flows downhill – This one seems easy, but you need to keep it in mind through the entire process.
  • Water must be kept inside the liner – Again, this sounds basic, but I see this part messed up all of the time.
  • Never twist heavy rocks on top of the liner – This will create holes that will allow the water outside the liner.
  • Avoid having folds of liner or rocks that will divert the water over the edge – This again seems like it might be too basic to mention, but it happens all of the time.
  • Electricity and water do not mix – Don’t get into ponds with pumps running in them. Failure of the pump or the electrical outlet while you are in the pond, could result in electrocution.

Before you Begin:

Location Planning

This is probably the most important step. Waterfall and stream construction is expensive and hard work, so it would be great to get it right the first time.

Consider the layout of your pond and its relation to the viewing area. The ideal situation would be that you have a hill on the side of your pond that is furthest from the viewing area. The viewing area is most likely the house, but if not, then wherever you will most likely be viewing the pond.

A hill on the backside of the pond allows us to build a waterfall or stream without needing to move a bunch of dirt, so it makes our lives easier. Unfortunately, this is not usually the case. Most ponds that I see are situated in a flat area. It is okay if this is the case; it just means more work for us.

We need the water to run downhill, and we want it to run toward our viewing area so that we can see it. Installing a waterfall or stream where you can’t see it is still very beneficial for the pond, just not as beneficial for you.

The ideal setup is a pond with a small hill behind it and an electrical outlet on the opposite side of the pond from the hill. This will allow us to build our stream or waterfall on the backside of the pond and plug our pump into the front side of the pond, giving us the best circulation.

Construction Steps

Base Preparation

We will need to prepare two areas of the pond. These areas need to be contoured to allow us to do our installation, and they need to be relatively free of rock, sticks, roots, or anything else that might poke holes in our liner.

On the backside of the pond, we need an area shaped somewhat like a trough that we can place our liner into so that the water will be kept in the liner.

If we are creating a stream, then a slowly meandering trough that starts wherever we would like it to start and ends in the pond would be great. This trough must pitch toward the pond and must not be lower than the top of the pond water at any point.

If we are creating a waterfall, then the hill must be higher, and the trough will look more like steps to allow the water to cascade down the steps. Once again, the waterfall should start at the high spot and end in the pond, but at no time can it be lower than the top of the pond water.

In both of these, the edges of the trough need to be high enough to support the liner so that the water remains in the liner.

The questions of how high the edges need to be and how deep and wide the trough needs to be are always dependent on how much water will be flowing through the stream or waterfall, and this is always dependent on the size of the pump.

Creating an attractive waterfall or stream requires at least 100 gallons per hour of water flow per inch of stream or waterfall width. So, if you want a waterfall that is two feet wide, you need to pump at least 2,400 gallons of water per hour. This is a minimum, and I would suggest more water flow.

Now that the backside of the pond where the stream goes is prepped, we need to prepare the front side of the pond to accept the pump. It is possible to buy a pump that is enclosed in a basket or filter and just toss it into the pond, but this will result in much clogging and much pump maintenance for you, and I assume that you would prefer less maintenance.

Whether your existing pond is lined or unlined will make a big difference in this step. If it is lined, we need to clear the stone, rock, and debris from the liner in the area where the pump will be. If it is unlined, I would recommend installing a piece of liner in the area where you intend to put the pump.

Prepare your pond accordingly. We want to install a culvert section into the pond to house the pump. We will then be covering the culvert with rocks to keep the muck and debris out of our pump.

For right now, clear out muck and debris and make an area that slopes down into the pond from the front edge (near the outlet).

Liner Installation

Once you have your base prepared, you should install the underlayment first. The underlayment is typically a geosynthetic material, but it could be almost anything that will protect the liner from being punctured. The underlayment should be everywhere that liner will come into contact with dirt.

After the underlayment is installed, the liner should be installed over the underlayment and pushed own into the trough. Be sure to always leave plenty of extra liner sticking up over the edges of the trough. Having too much liner is never a problem; we can cut it away at the end. Having too little liner can be the cause of long-term struggles and leaks.

If I am installing streams and waterfalls, I usually buy a roll of rubber that is ten feet wide. This gives me great flexibility in the design and size of the project. Remember that the liner will need to twist and fold to create turns and drops in the stream and waterfall. Also, the larger that your rock is, the wider your stream will need to be, and the wider your rubber will need to be. I’m not suggesting that you need a ten-foot-wide piece of rubber for every size waterfall or stream; I’m just suggesting that you plan to have significantly more than the width of your stream. Figure out what you think you might need, and then add a couple of feet.

Always have several feet of extra liner at the top of the waterfall and at the bottom to ensure that you do not run short.

I understand that rubber liner is expensive, but cutting corners on the amount of liner is the cause of so many problems later in the installation that I just need to stress the importance.

Push underlayment and rubber down into the pump area of the pond also, then place a section of a culvert on top of the rubber and pile rock on top of it until you can no longer see the culvert. Leave the top edge of the culvert exposed just below the top of the water to make it easy to drop the pump down the culvert. Make sure that the bottom of the culvert is protected with stone so that debris cannot get to the pump. Various sizes of stone are best to protect the pump.

Install Rock

Now we can install rock onto the liner of the stream and waterfall. The larger stones should be along the edges for the stream to make it look like a real stream and keep the liner in place. For the waterfall, the larger rocks must also be along the edges but must also be on the steps of the waterfall to create realistic-looking cascades.

At all times, while installing the rock, be sure that the edges of the liner stay standing up and don’t let any folds end up falling down behind the rocks. One fold that settles down behind a rock will be a tricky leak to find. Make it a habit to pull up on the liner after setting each edge rock.

Pay attention to the direction of water flow and the angles of the rocks you set. Don’t set any rocks that will form a ramp that will direct water out of the stream. If you have a rock with a sharp sloping angle on it, just face the angle downstream instead of upstream; this way, the water won’t flow up the ramp and out of your stream or waterfall.

Once all of the edge rocks are set, we can install some rocks in the waterfall area to agitate and direct the water. Once the larger rocks are installed, you can install the river gravel to fill in all gaps.

When installing the rock, you need to think about how the water will flow over and around the rocks, focusing on being sure that the water will not overflow the edge of the rubber and focusing on making the stream or waterfall look as natural as possible.

Install the Pipe

I always use flexible PVC pipe because it is much easier to install than rigid PVC, and it will flex a bit to avoid cracking. The pipe should be installed from the top of the stream or waterfall, around the pond’s edge, and into the culvert area to connect to the pump. I always leave the pipe very shallow, only deep enough to cover the pipe with dirt, mulch, or gravel. The pipe must be pitched toward the pond from the start of the stream or waterfall to the pump. The pipe will be connected to the pump using a PVC fitting. Many pumps come with a fitting.

The size of the pipe used is always dependent on the size of the pump, and more water flow requires a larger pipe. I typically use one-inch pipe for pumps up to 900 gallons per hour(gph), 1.5″ pipe for pumps up to 2000 gph, 2″ pipe for pumps between 2,000 and 7,000 gph, 3″ pipe for pumps that are larger than 7,000 gph, and 4″ for pumps larger than 12,000 gph.

At the top of the waterfall and the start of the stream, create a small bowl in the ground to push the liner down into. Push the pond pipe down to the bottom of this bowl and pile rocks and gravel on top to hold it down. This will allow the water to flow up through the rocks and create a natural-looking beginning to the falls or stream.

Run The Pump

Now is the point when you get your first glance at how the waterfall or stream might look and how the pump filter is working. Plug in the pump and watch the waterfall of stream closely. Since this is your first waterfall or stream, I would anticipate having some areas where the water flows over the edge of the liner. When you see these areas, turn off the pump, push dirt underneath the liner, and then run the pump again. Do this until you have fixed all the places where the water was running out.

At this point, if you think there are no leaks, I would let it run for a few hours and then recheck it looking for any wet areas and keeping an eye on the pond water level. A leak in the stream or waterfall will cause the pond water level to drop quickly.

Add Foam (optional)

Once you are confident that it is not leaking, you can turn it off and use the expanding pond foam to direct the water a bit. Never use the foam to try to keep the water in the liner; only use it to direct the water to go up and over some of the rocks so that you can see the water, rather than having it all run underneath the rocks. Remember, it is only a filler; it is not a water-tight seal, no matter what it says on the can.

I mostly use it under my cascade rocks to seal the bottom of the rock to the liner, and I will also use it to fill the gaps around the edge rocks next to the cascade rock. We are trying to block areas where the water can go under the rocks so that it is forced to go over the rocks.

Adding pond foam is certainly optional. Your pond, waterfall, and stream will function perfectly without any foam. The foam is only there for us to push the water up and over the rocks where we can see it better.

When working with the pond foam, wear rubber gloves, and please use it sparingly. It expands quite a bit and is sticky and very hard to remove from your hands.

After you have applied the pond foam and it is starting to dry, it may be a good idea to toss some gravel on the top of some of the larger foam areas so that it will stick and disguise the foam. This needs to be done before it finishes drying but after it sets for a little bit. Also, before it becomes completely dry and hard, you can push the expanding areas back into place to avoid having as much to clean away later. Always use caution when pushing on the foam; you want it to form a good seal between the rubber and the rock

Let the pond foam dry for a few hours and then push down or pull away any excess foam and disguise it with gravel.

Now, try to run the pump again. You will likely have raised the water level in the waterfall or stream, so you will probably have new leaks that you didn’t have before. Turn the pump off, push more dirt under the liner to stop the leaks, and then let it run once you think it is no longer leaking.

I would now let it run for a day and once again look for leaks.

Trim and Cover

Once you have the waterfall or stream running, you like how it looks and doesn’t leak; you can cut away the excess rubber. I typically leave at least 4″ of excess rubber along all edges and then let it run again. If it doesn’t leak, fold this excess rubber under or cover it with gravel, and you are done. Take a bit of extra time and be sure that all voids between rocks are filled with gravel. This will keep the mice out of your waterfall. Mice like to make nests in a hole over the winter, and they will chew holes in your rubber in the process.

Now you have a beautiful waterfall or stream in your yard, and I’ll be that you have some great ideas on how you would do it differently if you ever do it again. Who knows, you may just decide to do it again someday.

General Waterfall and Stream Tips

  • The balance of your pond relies on water movement, aeration, bacteria, and plants. The water movement and aeration provide oxygen for the plants, fish, and bacteria. The bacteria help break down debris that gets into the pond, and the plants take nutrients out of the water. The more attractive aquatic plants we have in our ponds, the fewer nutrients available for algae to grow. Now that you have a stream or waterfall, you have a great spot to install some aquatic plants. Put them on top of the rubber and under the river gravel without any pot. The roots will spread, and the plant will help to keep your pond clean.
  • Cleaning and maintenance of your waterfall or stream should be minimal. Most of the debris that gets into the stream or waterfall will end up in the pond. If you have a lined pond, you may want to pump it down and pressure wash everything every few years, but it is not entirely necessary. Cleaning helps to prevent large deposits of muck on the pond bottom. The stream and waterfall will almost certainly grow algae. Don’t panic; this is natural. Rather than spending time trying to scrub algae off of the rocks, which doesn’t work anyway, you should plant more plants and figure out how to keep excess nutrients out of your water.
  • Don’t ever fertilize the lawn around your pond; this will undoubtedly cause some fertilizer to run into your pond the next time it rains, which will be sure to grow a bunch of algae.
  • If you see a leak in your pond, it is almost always a stream or waterfall edge that has settled or fallen down. One way to tell if it is your stream or waterfall that is leaking or if it is your pond is to turn off the pump. If the water level keeps going down with the pump off, then your pond is leaking. If the pond is no longer losing water with the pump off, the leak is in the stream or waterfall.
  • If you do get rodent holes or tears in your liner, don’t worry, they can be patched. Just about every sort of pond liner has patch kits available. If you use rubber liner, it is just like patching a bike inner tube.
  • Add some low volt lighting to liven up your new waterfall or stream. Lights will give you a good show when the sun goes down. You can use waterproof lights under the water, which will make the water glow and shimmer, or you can use lights out of the water, which will give you a brighter, more sparkly shine. You can decide which one you like better.
  • Don’t resort to chemically treating your pond. By using chemicals, you are throwing the pond out of balance because you are killing off vital parts of the ecosystem. Only use completely natural bacteria to add to the pond. Using chemicals, even if the container says it is fish and plant safe, is killing microorganisms and algae. These dead materials sink to the bottom of your pond and add to the nutrients making your problems worse.

Raising Fish in a Backyard Pond

Raising fish in a pond

Raising fish in your garden pond is a good idea for many reasons. Maybe you just want to add a bit of color and life to your pond, perhaps you want help controlling the algae in your pond, or maybe you are interested in raising a source of food. Raising fish in your backyard pond is truly an easy and fulfilling endeavor, no matter your reason.

Pond Guidelines and Some Common Sense

Backyard pond is a very broad term. Your ability to raise fish in your backyard pond will depend on the type of pond you have in your backyard and the climate you live in.

From my experience, when people are referring to a backyard pond, it can be anything ranging from a small plastic insert filled with water to a large natural pond that spans acres.

So how do you know what types of fish you can raise in your pond? Well, this is where common sense comes in. You must realize that any fish that you put into your pond are likely to grow, and they are likely to reproduce, so you should plan accordingly or plan to remove some over time. Your fish have one significant limitation, and that is your pond. Their entire existence depends on the water in your pond. It’s not like they can just pick up and move if it gets too crowded or too dirty; their only options are to live or to die; the rest is up to you.

This article is going to be referring to naturally balanced backyard ponds. I will not get into the elaborate swimming pool-style filters and available systems, nor will I be considering chemical water treatments. When I think of a backyard pond, I think simple, not complex, and not chemically treated. It’s been my experience that mechanical and chemical treatments are never the answer and are typically just a waste of money and effort.

Some Characteristics of Good Fish Ponds

  • The pond must have an adequate amount of water. You would be surprised by the size of fish that I have seen living in tiny ponds. I have seen a dozen Koi, the length of your arm, living in a 10’x10′ pond that is 2′ deep. Vast amounts of water are not necessary to raise fish, depending on the type, but you should be aware that less water means more chance for fish to die off.
  • The pond should be of adequate depth. Whether you live in an area that gets very hot or very cold, you will want to have at least three feet of pond depth if you want to make your life easier raising fish. A bit of depth helps the fish have some water where the temperature doesn’t fluctuate as much.
  • The pond must have good quality water. For fish, water is life. You can compare their water to our air. Imagine how life would be if you were in a small box of air? Any minor changes to the air quality could significantly impact your quality of life. The same is true for fish and their water. Large fish in a small pond might be fine as long as the water quality is good, but if the water quality suffers, so will the fish.
  • The pond must have plants. They are the workhorses of this world. Plants clean our air, and plants clean your water. There is no maybe about this; it is a fact. Anyone trying to keep a pond that doesn’t have many plants growing in it is fighting a losing battle. Plants clean water, remove nutrients and provide cover and food for our fish. They are essential.
  • The pond must have some circulation. Larger bodies of water are circulated by wind and wave action and water flowing into them from rivers, streams, and springs. Our smaller backyard ponds typically lack any of these natural forms of circulation, so we should provide some circulation for good water quality and happy fish. All types of circulation also provide some aeration. The natural balance of the pond depends on aeration. All life in the pond must have a bit of oxygen to live, so no circulation means no aeration, which means no life. The more oxygen in the water, the more life it will sustain and the healthier it will be.
  • The pond should only take in clean water. All ponds will take in water from their surroundings, whether it is from a spring (if you are one of the lucky ones) or from rainstorms that wash runoff into our ponds. The cleaner this runoff water is, the better. If your backyard pond takes in runoff water from your lawn or farmed fields, it might be taking in chemicals and fertilizers. Trying to raise fish in a chemically-laden body of water will be difficult. Small amounts of pollutants will be easily taken care of by your plants, but large doses of lawn fertilizer or manure are sure to throw the pond out of balance.
  • The pond should be balanced. Speaking of balance, this can be the most challenging subject to understand and sometimes the hardest to attain. I’m sure that there may be a scientific formula for this, but I’m not a scientist, so I don’t have it if there is. I can tell you that from my years of experience, all bodies of water are either in or out of balance. A pond that is well balanced as nature intended will have clean water and healthy plants and animal life. A pond that is out of balance will show symptoms such as excess algae growth, cloudy water, green water, bad smells, and sick animals.

What Do I Mean by Pond Balance?

Pond balance encompasses all of the above essential elements needed for a pond. You likely see bodies of water all around your area that are either balanced or unbalanced. Most are probably not specifically managed by humans, but they are all affected by humans, to be sure.

Nature is constantly fighting for balance no matter where you look. Plants and animals across the globe are in constant competition for nutrition, air, and sunlight. Wherever we humans disrupt the balance, you can see nature fighting to get it back.

Our ponds will strive to balance themselves all on their own if we let them, but tiny little bodies of water that are not spring-fed will generally fill in over time if left to nature’s ways. Keeping small bodies of water chocked full of fish is not a natural occurrence, so to make it happen, we need to manage it a bit to help it survive well in nature.

Choose Wisely

First and foremost, choose wisely when adding fish to your pond. Adding a bunch of fish that are not suited to your pond size or temperatures is undoubtedly setting yourself up for failure. Research your fish choices and match them to your pond. Of course, it’s your land, so if you want to choose your fish and then build a pond to suit your fish, you can do that too.

Size Matters

Size matters when it comes to backyard ponds. In general, larger bodies of water are easier to balance than smaller bodies of water. Always err on the side of giving your fish more room than they need, at least in the beginning. You can increase fish load over time as you begin to understand how the fish and your pond work together.    

Add Plants

Add many plants to your pond of all varieties. Choose native aquatic plants that will thrive in your environment but avoid introducing overly aggressive plants that will tend to take over your pond. Aquatic plants tend to be a bit invasive to begin with, which is good because fast-growing plants remove many nutrients from the water, but it is terrible if you are in constant battle with your pond plants to keep them in control.

Provide Surface Area

Provide surface area. A big part of the pond’s balance is the microscopic bacteria that live in the pond. These bacteria are at work 24 hours a day, breaking down debris and taking in nutrients. They need surface area to survive, so having rocks, gravel, and plants in your pond will help with this. Ponds with bare rubber liners are at a disadvantage due to their lack of surface area. More surface area will mean that more bacteria can survive in your pond.

Provide Circulation

Provide circulation. Water circulation is of vital importance to the health of your backyard pond. Unfortunately, circulation typically involves some sort of a pump. Some systems use wind and solar power to run these pumps. We can circulate water from the bottom of the pond to a stream or waterfall where it flows back into the pond; we can circulate pond water through a wetland filter which is a great way to clean water and aerate it at the same time. We can also circulate water through the use of bottom or surface aeration.

Bottom Aeration

Bottom aerators work by setting a small air pump at the edge of the pond that pumps air through hoses to diffusers at the bottom of the pond. This is the same principle used in fish tanks when you see all of the tiny bubbles rising up to the surface. By pumping air to the bottom of the pond, we are adding oxygen to the deeper pond water, which makes the bacteria more effective at breaking down debris and it also circulates the pond water. The bubbles that rise through the column of water cause the water to move with the air, and that will cause the entire column of pond water to circulate from bottom to top.

Surface Aeration

Surface aeration is usually accomplished through the use of a floating fountain aerator. This is simply a pump mounted to a float that shoots water into the air, and this aerates and circulates the water.

Add Life!

Your pond needs LIFE! When I talk about life in a pond, most people think about frogs and fish. While these are undoubtedly excellent animals to have in your pond, they are just the tip of the iceberg when it comes to life in your pond. The amount of living things in pond water is truly amazing, and all of these living organisms play a role in the balance of your pond. Things such as protozoa, arthropods, diatoms, amoeba, paramecium, rotifers, and amphipods are just a few. For a great glimpse into the life in pond water, check out this fantastic site full of information:

Don’t Be Your Pond’s Worst Enemy

Humans are often a pond’s worst enemy when it comes to water quality. We really only acknowledge what we see, and if we see something that we think is a problem, we want a quick fix. Unfortunately, nature doesn’t work with quick fixes; nature always works on long timelines. We see a bit too much algae in our ponds, and we think that we need to kill it before it gets out of control. This is the absolute wrong way to think about algae. Excessive algae in a pond is not the cause of your pond problems; it is a symptom of too many nutrients in the pond water. We want algae in our ponds because it is part of the pond’s balance. We don’t want excessive algae, so we need to have a good quantity of aquatic plants and animals to help control the algae, and we want to limit the amount of nutrients entering our ponds.

There are No Good Quick Fixes

Far too often, humans look for a quick fix and find some chemical that claims to be safe for fish. They dump it in the water, and the algae dies. They think they have won the war when, unfortunately, they have just taken an enormous step backward. Sure, the alga died, but it also sank to the bottom of the pond and began to decay. This means it will be fertilizer for the next round of algae that will return as soon as the nasty chemicals wear off.

Again, I am only talking about the things that we can see. The chemical industry has built it’s industry around hoping that we buy their claims of safety. I’m sure that you are not foolish enough to think that this chemical you dumped into the pond water only affects algae and nothing else, are you? That would be like saying that spraying toxic chemicals on our food crops won’t have any detrimental health effects or like saying that spraying toxic chemicals into the air to kill insects won’t also kill the birds and the bees and probably us over time. It’s true; any toxic chemical added to your pond water will be killing many other organisms that we can’t see without a microscope. All of these organisms take part in the balance of your pond. Don’t ever put any chemicals into your pond!

On to the Fish

Being a person who has installed and managed many decorative backyard water features in my life, I can say that I definitely have more experience with ornamental fish than any other type, so let’s start there.

Decorative Pond Fish

Goldfish: Goldfish are the most common decorative pond fish that I see for several reasons. They are very cheap and easy to get, they multiply like crazy, and they are pretty tough to kill. If you wonder if your pond will support fish, throw in a few tiny goldfish and see how it goes. Chances are, in a few years, you will have many more, and they will be thriving.

Koi: Koi are probably the second most common decorative fish I see. People seem to love their Koi. Maybe it’s their calm and mellow demeanor, perhaps it’s their bright colors, or maybe it’s because they can grow to the size of a young child. Koi are a very close relative to the common carp, so they are relatively hardy creatures, but I can tell you from experience they can’t hold a candle to goldfish.

Golden Orfe: These are schooling fish, so you will want to have at least five fish.  They seem to survive well and honestly look a lot like long goldfish.

Best Fish Commonly Raised for Food:


Tilapia are hardy fish with a diverse diet. They have adapted to grow outside of their native range, are excellent eating fish, and are fast-growing, reaching up to 1 pound in five to seven months. 

The Government of Sri Lanka introduced a program supporting small-scale fish farming, i.e., in backyard ponds. The average Tilapia production was 9,192 kg/ha, and the profit margins were very attractive due to the organic conditions under which the fish were raised. (Pushpalatha, Chandrasoma, Liyanage, Fernando, & Jayabahu, 2016). The widely grown hybrids of Tilapia are:

  • Blue Nile Tilapia (Nilotica, mango-fish, Boulti), 
  • Red hybrid Nile Tilapia
  • Stripped Tilapia


Catfish are one of the easiest fish to raise in the beginning of pond fish farming due to several reasons: 

  • Very fast-growing, can be harvested after three months when appropriately fed.
  • Highly tolerant to low DO (dissolved oxygen) levels in water
  • Resistant to high ammonia levels in the water, they do well even when stocked at higher densities.
  • They are bottom feeders and prefer a pond with large flat bottoms to make feeding easier. These are valuable scavengers that are easy to raise and breed.
  • They are non-territorial and can live happily with Tilapia, Perch, Bluegill, etc.
  • Prefer water in the range of 75-85˚F, but survive in much lower and higher temps.
  • Channel catfish range from Northern Mexico to Southern Canada, mainly in the Eastern US.

Largemouth Bass:

  • Largemouth Bass is a top feeder, eats almost everything, including worms, pellets, and insects.
  • Tolerates a wide range of temperature fluctuations (65-85 ˚F), prefers alkaline but clean water and is resistant to high nitrate levels.
  • A good choice for growers who cannot change fish species between the warm and cold seasons.
  • Carnivorous species that will eat the sluggish Tilapia and Catfish in the winter, keeping the pond water clean and the pond population in control.


  • A Great-tasting fish and a rich source of Phosphorus, Carbohydrates, Omega-3 fatty acids, and Sulphur.
  • Not easy to grow, they take more than two years to reach harvestable size.
  • Need water depth of at least 10′ to survive.
  • Need water temperatures between 40 and 50 °F.
  • You will need to feed them as they won’t likely find enough food in your pond. 


  • Also named as “Bluegill sunfish, copper bellies, copper heads,” etc., is q popular freshwater game as well as food fish in the Central and Southern United States.
  • The maximum length it attains is 15-23 cm and less than 0.25 kg.
  • Prefer water temps 65-80°F


  • Carp is also a widely farmed pond fish in the United States, both for food and ornamental purposes.
  •  It contains little intramuscular bones within the fillet, which makes some folks hesitant to eat it, but it is a tasty eating fish if prepared properly.
  • Easy to raise and lives in almost every area of the world. 

Best Fish Pond Plants:

Pond plants should be the best oxygenators, create smooth underwater habitat for the aquatic animals, release oxygen directly into the water while absorbing carbon dioxide from water, grows on the fish waste, etc. (Rahmawati, Dailami, & Eka Supriatin, 2021)

Submerged pond plants:

  • Fanwort (Cabomba): its smooth, delicate leaves cushion the docile fish during movement.
  • Hornwort (Anthocerotopsida)
  • Anacharis or Elodea 
  • Eelgrass (Vallisneria): completely (partially) submerged pond plant, hardy plant that regrows from its parts damaged by pond fish, said to be the best oxygenator, fish waste absorbent plant.

Partially Submerged or Floating Plants:

Emergent plants grow efficiently in small ponds as they require shallow waters for root anchorage while the foliage and flowers show at the surface. (Huang, Zhang, Bai, & Qin, 2017). Some of the fish pond friendly emergent plants are mentioned below:

  • American lotus
  • American water plantain
  • Arrowhead
  • Beak sedge
  • Cogon-grass 

Water Quality Standards to support Fish Growth and Development:


Because fish are cold-blooded animals, water temperature is one of the most critical factors in the growth, breeding, feeding, behavior, and survival of any fish species. The fish will grow and reproduce happily within the optimum range and tolerance limits. Below are some fish types and their temperature requirements.

Key: in degrees Fahrenheit

LWT (lethal water temperature)

OWT (optimum water temperature)

STP (spawning temperature range)

 Fish type

  • Nile Tilapia: LWT 54-100, OWT 81-86, STP 72-73 
  • Common Carp: LWT 36-97, OWT 73-79, STP >64
  • African Catfish: LWT 54-100, OWT 77-81, STP 68-86
  • Largemouth Bass: LWT 36-95, OWT 73-86, STP 63-68

Dissolved Oxygen:

The dissolved oxygen levels in your pond will determine whether the fish will survive or not. Below are some examples of the needed DO levels for these fish. 

 Fish species Preferred/recommended DO level

  • Tilapia: 4 mg/l
  • Common Carp: 3 mg/l
  • African Catfish: 5 mg/l
  • Rainbow trout: 8 mg/l


Cloudy or muddy water is turbid, and it can be a problem in newly established ponds and typically decreases when the pond plants have grown properly. Below are a few tips to control turbidity.

  • Do not stock the pond with species that stir up the bottom, e.g., the common carp, etc.
  • Plant vegetation in the pond. Once again, plants come to the rescue.
  • Rock the bottom of the pond

Benefits of Freshwater Fish Ponds to the Environment:

  • They enrich, support, and maintain a healthy ecosystem. 
  • They help conserve water.
  • They can be a productive and profitable hobby for the homeowner.
  • They can provide a healthy and organic, protein-rich food source for your family at a reasonably low cost.


Huang, P., Zhang, D., Bai, S., & Qin, S. (2017). Application of combined emergent plants in floating bed for phytoremediation of landscape pond in South China. International Journal of Environmental Technology and Management, 20(1-2), 22-36.

Pushpalatha, K., Chandrasoma, J., Liyanage, H., Fernando, W., & Jayabahu, J. (2016). Farming of Nile tilapia (Oreochromis niloticus) in backyard ponds in Sri Lanka: Culture practices, fish production, and profitability. Sri Lanka Journal of Aquatic Sciences, 21(1).

Rahman, M. M. (2015). Role of common carp (Cyprinus carpio) in aquaculture production systems. Frontiers in Life Science, 8(4), 399-410.

Rahmawati, A., Dailami, M., & Eka Supriatin, F. (2021). The Performance of Water Quality in Tilapia Pond Using Dutch Bucket and Deep Flow Technique. Egyptian Journal of Aquatic Biology and Fisheries, 25(1), 885-897.

Towers, L. (2015). How to achieve good water quality management in aquaculture. The Fish Site.

Large Natural Ponds

Large natural pond with ducks

The term “Natural Pond” indicates a harmonious and balanced setting where plants, animals, microbes, and water support each other to develop, decompose, and regenerate. Many natural ponds are man-made and completely natural, created by mother nature herself. For the most part, when referring to natural ponds, we are talking about ponds with an earth bottom with no synthetic liner that is naturally maintained with no use of chemicals, filters, or pumps. 

This article will explore some of the similarities, differences, and environmental impacts of these various types of Natural ponds.

Biological Ponds

All natural ponds, big or small, can be classified as biological ponds. You really can’t maintain a body of water without any biological processes taking place, even if you spoil the water with high doses of chemicals; eventually, the chemicals will wear off, and the natural biological processes will take over again.

All biological (natural) ponds are cleaned and maintained by microorganisms, plants, and decomposing bacteria. The microorganisms utilize the contaminants present in the forms of heavy metals, organic, and inorganic substances, helping to reduce the pond water pollution and clean the water.

Aquatic Plants

All-natural (biological) ponds rely on plants to keep them clean. The plants in the pond play a critical role in balancing a biological pond, taking in the nutrients, and cleaning the pond water of pollutants. These plants are classified according to the functions that they perform for the pond. 

  • Oxygenating pond plants such as Hornwort and Water Thyme help our pond balance by taking in nutrients, adding oxygen to the water, and providing shelter for spawning and small water creatures of all types.
  • Floating plants are typically heavy feeders and fast growers that provide fish and shade for the pond water. Plants such as Water Lettuce, Floating Fern, Fairy Moss, etc., will suppress the algae growth by absorbing the nutrients and being in direct competition with algae. 
  • Bottom growing plants with long tubular stems such as lotus and water lilies help take nutrients out of the water and help to shade the surface of the water, which reduces algae and keeps the water cooler.
  • Marginal Aquatic plants would include the reeds, rushes, and grasses that grow in zero to ten inches of pond water. These plants also remove nutrients from the water, shade the water, provide cover for animals and help to reduce sediment runoff into ponds.

Plant Basics

  • Pond Plant Coverage: Every small or large pond should have 60-70% of aquatic plant coverage.
  • Extensive root system: The integrated root system will absorb the nitrogen, phosphorus, and other elemental pollutants from the pond water and act as a storage house for suspended solids.
  • Attractive plants: It’s a fact that the more beautiful pond plants we have in the pond water, the fewer algae will be present. Flowering and beautifully colored pond plants such as water lilies, Iris and Taro, beautify our ponds, clarify our water and provide habitat for wildlife of all types.


Bacteria and organisms in the pond work tirelessly with the pond plants to help keep our water clean. Adding supplemental aerobic and anaerobic bacteria to any pond will help to speed up the process of breaking down the debris in the pond, which will, in turn, make those nutrients available for the plants. The bacteria, enzymes, and other microscopic pond inhabitants consume nutrients to live.


As we have described above, the natural ponds can only maintain themselves if they are in balance. A proper measure of water, plants, and wildlife will allow a natural, biological pond to balance itself without the interference of humans. Any chemicals added to the pond will affect this balance and disrupt the natural processes that are helping to keep the pond clean.

Case study related to Biological Ponds

A Large natural pond will have the highest Biodiversity present in an area. The Global Conservation Policy to protect biodiversity promotes all kinds of ponds, either large natural ponds, small backyard ponds, or constructed wetland filtration systems. 

The relationship between size and diversity for 80 ponds in Switzerland using aquatic plants, aquatic animals, and their richness (number of species) and conservation value (no. of species and their rarity) were studied.

It has been found that the small biological ponds contain more species and higher conservation values than a single large pond. (Oertli et al., 2002). I would surmise that this is due to the relatively larger amounts of plants in small ponds. 

Types of Natural Ponds

There are multiple natural pond types that are all more similar than different. They all rely heavily on biological processes and balance to maintain themselves.

Waste Stabilization Ponds

These ponds do their work through the natural water treatment process involving the ultraviolet radiations in sunlight, high temperature, pH fluctuations (due to algal photosynthesis), and plant biome to inactivate the pathogens, reduce the BOD, stabilize the pollutants present in wastewater. (Ho, Van Echelpoel, & Goethals, 2017)

Existing wastewater cleaning technologies and equipment are costly and require a large amount of energy to run the pumps, agitators, and mixers. 

By utilizing the natural processes described, the stabilization ponds can safely and economically turn chemically laden and polluted water into water suitable for irrigation and to release back into the groundwater if given enough time.  

When cleaning water without any circulation or agitation, the process simply takes longer, but this is not a reason to avoid using these ponds; it is merely necessary to realize and acknowledge that mother nature takes time to fix our imbalances.  

Importance and Applications

This wastewater treatment strategy is widely practiced in countries that have warm climates. Anaerobic ponds (removes almost half to 2/3 of BOD), Facultative ponds (maximum decomposition of organic matter and removal of other pollutants), and Maturation ponds (placed in series only when highly efficient removal of pathogens is required) are designed in series for the efficient treatment of wastewater. (Coggins, Crosbie, & Ghadouani, 2019)

These ponds help mitigate the increase in the level of diseases caused by drinking unhealthy and heavy water due to the improper disposal of human and animal wastewater and the dumping of industrial pollutants.

Rather than these contaminated waters being dumped directly into lakes and rivers, they can instead be diverted to the treatment ponds to allow the needed time for them to regain their biological balance.

Waste stabilization ponds require large areas and hot climates. They are most often used in the Southwestern US or hot areas of other countries. 

It is a time-tested process that cannot be established in towns or cities but instead requires more rural settings for their installation.

Waste stabilization ponds can treat sewage, industrial, and almost all kinds of wastewater.

During the treatment processes, nitrogen, phosphorus, heavy metals, suspended solids, and pathogens are removed to a level that makes the water safe for use as irrigation water. 

Retention ponds

These ponds are man-made and are natural bottomed. They are strategically placed near developed areas to alleviate storm runoff and flooding concerns. These ponds take in the runoff water, which may contain sediments, fertilizers, and various hazardous chemicals given off by industry, automobiles, etc. The water is held in these ponds and allowed to slowly be treated by plant material, bacteria, and other pond organisms, just as with any other natural pond.

Sometimes these ponds are helped along in the process by first allowing the water to run through or over constructed wetlands.

Constructed Wetlands are shallow water biofilters that use the natural potential of hyper-accumulator plants and either surface flow or sub-surface flow to clean water. Rooted plants along with gravel and sand are used to absorb, stabilize, evaporate, or degrade the pollutants in wastewater. The water slowly passes through the media, allowing the suspended solids to settle out and the contaminants to get absorbed and remediated by the plants. These constructed wetland systems are often used to clean greywater, Industrial-waste-water, Municipal-waste-water, and storm-water runoff.

Natural Wildlife Ponds

These are ponds built specifically to encourage animal inhabitants, creating a more biodiverse environment. “Nature will grow under Natural conditions” is the phenomenon behind every natural wildlife pond. This is a pond in which no chemicals, filters, or pumps will be used while supporting the growth and development of animal and plant life at the same time and a low cost. (McCance et al., 2017)

Once again, the pond’s health is mainly dependent on aquatic plants. The pond plants provide oxygen, absorb carbon dioxide, phytoremediation pollutants, and provide cover for animals of all types.

Selecting Native plants, especially the Native Grasses, is often a great way to get the ecosystem of a new pond started. The native grasses establish quickly and help to encourage further plant growth and minimize erosion. Examples would include; Feather-grass, Zebra-grass, Silky-thread-grass, Ruby-grass, Northern-sea-oat, etc.

A wildlife pond is helpful in the conservation of urban and suburban biodiversity by providing food, shelter, breeding habitat, and food-chain sustainability.

Shallow regions are planted with marsh and littoral plants (Spiny-rush, Cattail, Fat-hen, Bullrush, Alkaliweed, etc.), while the Creeping Phlox, Kangaroo raw, Blanket-flower, Sedum, Columbine, etc. These are good all-around pond perimeter plants to attract wildlife. 

Natural Fish Ponds

The difference between a wildlife pond and a fish pond may be nothing at all except that some natural ponds are built and maintained specifically to raise fish.  

A fish pond will usually have some deeper areas for the fish and underwater structure to encourage spawning and provide cover.

In natural fish ponds, fish will eat, live, poop, and die, all in that one body of water. For any of you who have had a fish tank, you realize that this is no small feat.

The dead bodies of fish, their excretions, and any debris that falls in the pond add nutrients to the water. The only way to control the water quality in natural fish ponds is through the use of aquatic plants and proper fish stocking.

Algae grow by utilizing these nutrients from the pond water, and if left unchecked, may tend to take over the pond. Selecting bottom and vegetation feeding fish will help nature take care of some of the algae, but the heavy lifting, as with all of the other biological ponds, is always done by the pond plants.

Historically, fish ponds were a way that a family or community could raise more livestock for human consumption that is easy to maintain and readily available for harvest, no matter the season of the year.

Some examples of large fish ponds which were used to compensate the food needs of local inhabitants as well as to earn profit by selling the aquaculture are listed below:

  • The Fish pond of La Cambre Abbey in Brussels.
  • Chinese Garden of Friendship in the Sydney.
  • Hawaii, USA, native Hawaiian used them extensively.
  • Coarse Fishing pond in England

The question is how to maintain a balance between the number of nutrients and algae growth? The answer is “through the wise selection of pond plants.” They will take up the excessive nutrients from pond water before being taken up by the algae through their extensive root system and efficient phytoremediation properties. Microorganisms, also called Biofilters, play an essential part in keeping the pond water clean and clear. (Thi Da et al., 2020)

Koi Ponds

Koi ponds are often built specifically for Koi fish. The Koi is a Japanese relative to the common carp. People enjoy their mellow and relaxed demeanor as well as their bright and flashy colors. While constructed specifically for the fish, most of these ponds end up being naturally maintained biological ponds as well. It is undoubtedly true that Koi purists may believe that the Koi require a smooth-sided, man-made, mechanically, and chemically treated pond; it is certainly true that these fish can live quite happily in natural biological ponds as well. They simply aren’t as easy to see and interact with in natural ponds due to the plant cover.

Due to the pond owners ‘ lack of education and impatience, many mechanically and chemically maintained ponds are simply over-complicated and over-treated. Humans are often too impatient to wait on mother nature to balance their ponds, so they go to great lengths installing mechanicals and dumping in chemicals in an all too often futile attempt to clean their pond. This is really too bad because nature will gladly do all of the heavy lifting if we just give it time.

Some examples of Mechanical Systems used in Koi ponds:

  • Biological filters: Sand filter, Trickle filter, Crossflow filter, etc.
  • Ultraviolet light: Used to sterilize the water from free-floating bacteria, pathogens and eliminate the algae by breaking it into clumps and then removing it using the mechanical filters.
  • Install a Bog into the Pond: This is a manufactured solution that is almost natural and should be used in virtually any pond with water quality issues. Floating natural bogs do an excellent job filtering water and removing nutrients and contaminants. In a koi pond, we can float man-made plant islands in the water, which mimic the natural bog and may contain plants such as Holy rope (Eupatorium cannabinum), Bead-fern (Onoclea sensibilis), Water Iris (Iris pseudacorus), Horsetail (Equisetum arvense), Day lily (Hemerocallis spp.), etc. (Nordbakken, Ohlson, & Högberg, 2003)


Coggins, L. X., Crosbie, N. D., & Ghadouani, A. (2019). The small, the big, and the beautiful: Emerging challenges and opportunities for waste stabilization ponds in Australia. Wiley Interdisciplinary Reviews: Water, 6(6), e1383.

Ho, L. T., Van Echelpoel, W., & Goethals, P. L. (2017). Design of waste stabilization pond systems: A review. Water Research, 123, 236-248.

McCance, E. C., Decker, D. J., Colturi, A. M., Baydack, R. K., Siemer, W. F., Curtis, P. D., & Eason, T. (2017). Importance of urban wildlife management in the United States and Canada. Mammal Study, 42(1), 1-16.

Nordbakken, J., Ohlson, M., & Högberg, P. (2003). Boreal bog plants: nitrogen sources and uptake of recently deposited nitrogen. Environmental Pollution, 126(2), 191-200.

Oertli, B., Joye, D. A., Castella, E., Juge, R., Cambin, D., & Lachavanne, J.-B. (2002). Does size matter? The relationship between pond area and biodiversity. Biological Conservation, 104(1), 59-70.

Thi Da, C., Anh Tu, P., Livsey, J., Tang, V. T., Berg, H., & Manzoni, S. (2020). Improving productivity in integrated fish-vegetable farming systems with recycled fish pond sediments. Agronomy, 10(7), 1025.

Detention Pond and Retention Pond: What Are They?

Retention pond after a rain

Detention ponds (dry ponds) and retention ponds (wet ponds) are two different types of water management ponds. In summary, both ponds aid in flood control and stormwater runoff treatment. They collect excess water and hold it for a period of time to help control erosion and water quality. 

 Sediment and bacteria, metals, nutrients, and other suspended solids settle out of stormwater in the ponds. These ponds can restrict and prevent the transport of pollutants to lakes or streams during storms.

 The Difference Between Detention and Retention Ponds

 The most significant distinction between a retention basin and a detention basin is whether a permanent body of water or pond is present.

 Retention ponds

  • These ponds typically hold water all year round.
  • Always contain a riser to allow for excess water to flow out during rain events.
  • Always have an emergency overflow area where the water can rush out without eroding to pond edge in the case of an extreme storm event. 
  • Water levels fluctuates due to water runoff and precipitation from the surrounding areas.
  • Keeping a pool inhibits resuspension and maintains accumulated sediments on the floor of the holding area.

 Wet retention ponds are a form of stormwater management that collects and treats polluted stormwater runoff. They regulate the quality and quantity of stormwater through the retention and storage of stormwater runoff. By holding the water, the pond’s natural mechanisms then remove pollutants.

 Properly graded pitches and a system of underground pipes links storm drains and divert the water to a wet retention pond. These structures direct significant quantities of water to the pond, while the outlet releases lesser amounts of water as required to keep the water level at the optimum level.

 Standing water is still a source of concern from a health perspective. Standing water can be a potential drowning risk, especially for children. Mosquitoes can breed in the stagnant areas of any pond, which can lead to mosquito-borne diseases. When designing retention ponds, developers should always plan for safety ledges, circulation, and maintenance plans to avoid these pitfalls. 

It is important to remember that each new retention pond creates a new habitat and haven for animals. If appropriately designed, they will improve water quality, reduce flood concerns and erosion, and raise surrounding property values. 

Too often, wet retention ponds are installed with the right intention but then never maintained or maybe over-maintained, leading to an unhealthy environment.

The retention ponds that exist in more wild settings that are allowed to grow beneficial aquatic and surrounding plants do an excellent job of filtering and cleaning water.

When the retention ponds are located near subdivisions, they are all too often mismanaged, which leaves them full of fertilizer runoff, void of beneficial plants, and chemically treated in an attempt to eliminate the symptoms caused by the mismanagement.

Detention Ponds

  • These ponds are dry for the majority of the year.
  • Always have outflow pipes and chutes to allow for storm water to flow through.
  • Will always have protected emergency spillways to avoid erosion and failure during extreme weather event.
  • Water will slow and stand in them during storm events.
  • They are used more to control and slow stormwater runoff than to retain it.

In dry areas, detention ponds (or dry ponds) are more prevalent and function as significant flood control structures. They are normally dry, save for times when snow is melting or rain is falling.  

Their main objective is to slow down the water flow and hold it for a limited time—at least 24 hoursThis allows enough time for soil particles and related contaminants to settle out. These systems are used in urban environments to minimize peak runoff levels caused by storms which will help to alleviate flooding.

Dry ponds may be developed to accommodate a wide range of storm occurrences and uses. Designers will consider slopes, watershed areas, plant material, etc., when specifying the layout and size of a new detention pond. In addition, an emergency spillway is typically needed to ensure protection during floods.

The basins are essential for storing and controlling stormwater runoff velocity from surrounding areas, especially in places where asphalt or concrete construction occurs. Stormwater runs much more quickly from these surfaces than from the naturally vegetated ground, so it must be diverted and slowed down to prevent excess sediment transportation and erosion. 

The amount of water that can be cleaned and treated is dependent on the size of the basin. Only flood flows are regulated by dry basins (detention basins). By eliminating contaminants and sediments, a retention pond can help to improve water quality.

 Dry detention ponds are most effective in locations with ten acres or more of land. The large expanses of land will collect more runoff and make a detention pond more of a necessity. 

Dry retention ponds typically have a very minimal slope to divert water. The inlet must be no more than fifteen percent higher than the outlet to ensure the proper amount of water flows into and through the system.

This facility functions by providing a large space for water collection. The water eventually flows out the bottom of the structure through the outlet or soaks into the ground. Concrete and other objects may be used as buffers to slow the flow of water and collect debris. 

Dry detention basins are advantageous as stormwater control devices for many reasons. They are less expensive to install than a wet retention pond since they occupy less space than other solutions, and they are fairly straightforward when it comes to design. When properly positioned and built, they can efficiently minimize peak rate and volume to pre-development levels.

 It is important that the plants in and around the detention basins can tolerate both dry weather and standing water for a while so that they can survive the environmental extremes that these basins encounter.

The downside of detention basins would be that they take up a considerable amount of real estate that can’t really be used for any other purpose other than maybe nature walks. The built structures may make the land they are on less desirable for sale and limit the potential for development. Many people will see this as a downfall, not understanding the valuable service they provide, ensuring the long-term stability of the area. 

While different in function, people often prefer a retention pond that holds water and provides a valuable water body. 

 General Maintenance and Problem-fixing Tips

 One of the most important things for both basins is to ensure that the overflow and outflow devices do not get clogged or blocked. This is one of the most critical maintenance tasks since the ponds and basins will work effectively only if the pipes are kept free of debris. Ensuring regular upkeep for detention and retention ponds will save money in the long run.


The type of vegetation in the basin’s surroundings will significantly affect the level of maintenance required. Too often, surrounding homeowners who don’t understand vegetation’s role in water filtration will mow their lawns right to the water’s edge. This encourages more debris and pollution entering the pond and promotes fertilizer runoff into the pond.

Some Maintenance Tips for Retention Ponds

  • Retain and encourage a band of tall un-mowed vegetation surrounding the pond to aid in the filtering and cleaning of water.
  • Remove any trees or saplings that may obstruct outflow structures.
  • Never fertilize the lawns in the ponds’ watershed. Chemical fertilizers are certainly not natural to pondwater and will upset the pond’s balance, always resulting in an algae-laden pond.
  • Aquatic plants and terrestrial plants are essential for water cleaning, but the introduction of invasive plants such as cattails can lead to increased long-term maintenance as some of these plants will grow out of control and end up filling in the pond over time.
  • Be sure that native or easy-to-maintain species are planted in slopes, banks, and other vegetation-friendly areas. 
  • Maintenance must always include repairing any areas that have experience soil erosion. Look for gullies and other problems on the bank a few times a year and after severe storms.
  • Reseeding areas with exposed soil, particularly on slopes around the site, will help to prevent erosion.
  • In areas where erosion seems to re-occur, rip rap and sediment barriers should be installed to prevent future erosion events.
  • Always remove debris and sediment from pipes to maintain their satisfactory operation.
  • Remove the debris or prevent debris from entering the pond to help alleviate outflow clogging problems.
  • In the case that excess sediment has changed the ability and function of overflow structures to function correctly, it must be physically removed. 
  • Fertilizers, pesticides, or herbicides should not be used in or around the facility. Chemicals pollute the water and may encourage the growth of undesirable plants.

A Note on Algae

 As temperatures rise and the nutrients in the water increase, algal blooms become more frequent. Nutrient levels rise when manure, pollution, and runoff enters the water.

 There are potential toxic algae blooms, but these are very rare. For the most part, excess algae is simply a symptom of an unbalanced pond.

Humans tend to believe that the algae needs to be killed when it actually needs to be controlled, not killed.

Algae is a natural part of the pond ecosystem that can easily be controlled naturally, using proper maintenance as listed above and potentially increasing water flow and oxygenation using aerators. 


 Mosquitoes prefer to lay eggs in and near standing water; Aedes aegypti (a mosquito that spreads the Zika virus) is regarded as a “container-breeding mosquito.”

 To minimize the mosquito breeding areas, the introduction of aeration and water circulation is suggested.

According to studies, female mosquitoes tend to lay eggs in collected water or water in human-made containers.


Pond Water Aquaponics – Growing Food in Your Water Garden

pond water aquaponics

What else could be more beneficial than growing vegetable/food crops using the water existing in your own backyard? This smart technique is known as Pond Water Aquaponics. You do not need to fertilize your crops or water them periodically because they will receive the nutrients and water from the pond. The most important output of small-scale aquaponics production is vegetables.

Over the past 30 years, the use of pesticides and synthetic chemicals has increased so much that it seems the growers have started thinking it’s impossible to grow something or anything without applying chemicals. This makes it hard for folks to even purchase vegetables without wondering whether they are poisoning themselves in the process. Luckily for us, it is possible to grow our very own vegetables in our yard by using our pond or water garden.

The System Required For Pond Water Aquaponics:

People having backyard ponds are rarely aware of the concept of growing veggies using that pond water. Ponds are the ideal source of nutrients, especially if they contain freshwater fish. 

To have a successful pond aquaponics system, you need two parts:

  • Aquaculture for aquatic animals – if you have a pond with any animals, you already have this part. This is where we will get the needed water and fertilizer for the plant.
  • Hydroponics for growing plants – This is the part where we need to get creative and find a way to grow food sources in the water from our pond.

Typical Components of an Aquaponics System: 

  • Rearing tank – This is traditionally where the fish are raised. For us, it is the pond.
  • Settling basin – This area is used to collect the uneaten fish food and remove biofilms and any other kind of sand, rock, or waste in the water. For us, the pond bottom or perhaps an intake basin will do.
  • Biofilter – A system that uses living elements like nitrifying bacteria to decompose the pollutants and nutrients and convert them into food for the plants. This might be a wetland filter, floating island, or any sort of strata that will encourage bacteria colonization.
  • Sump – The last and the lowest part of the system collects the additional water to recirculate it back to the tank or pond.

Typical Components of a Hydroponic System:

  • Media bed using cotton wool –  Often used by home gardeners. It contains a rectangular tray with compartments and holes at the bottom. The spaces are covered with wet cotton wool to conserve moisture. These are often used to start seeds inside the home or a greenhouse before it is warm enough outside to plant. Although the root areas will overgrow the containers, they can also be used as long-term planting structures for this system.
  • Nutrient film technique – This consists of a net cup filled with gravel or any other growing media, an extender, and a grow tube. The system works well for ponds and streams because it is easily installed, provides proper air and water circulation, and produces healthy plants.
  • Deep water culture – Utilizes no medium, just a mesh cup or pot with gravel to support the seedling. This can be used individually or within a tray system for multiple plants.

The Potential of a Constructed Wetland Filtration System:

Constructed wetland filtration systems are typically installed in or near bodies of water to utilize marginal aquatic plants to filter and clean the water. Water is pumped from the body of water, and either pushed up through the filter from the bottom or simply ran over the system’s top. We can utilize the wetland filter model to grow our vegetables rather than merely cleaning water using pond plants.

  • The pond water cleaning plants are now your vegetables
  • You might want to continue to use aquatic plants and simply add your vegetables to areas not already crowded with aquatic plants
  • You may need to clear aquatic plants and their roots out of the areas where you would like to grow your vegetables
  • Wetland filters are typically already in full sunlight areas, so they are great for vegetables
  • The vegetables never need water and get their fertilizer from the pond water.
  • They work very well for leafy vegetables like Lettuce, Spinach, Cabbage, Kale, Coriander, etc.
  • Wetlands are typically topped with small gravel just below the water level. For growing vegetables, you will likely need to add more gravel. The system is areas to create growing conditions suitable for your veggies. Aquatic plants typically like 1 “-10” of water over their roots, which is not the case with vegetables.
  • For the best results, you will want to start with seedlings rather than sow seeds into the gravel.

The Potential to use the Pond Edge or Border

Not every pond will have a constructed wetland filter, and not every homeowner will want to spend the time and money to build a wetland filter, so the previous section may not apply to you. One thing that every pond owner has is a pond edge or border. 

  • You will want to start with seedlings rather than seeds.
  • You will need to use some sort of container or gravel to hold the seedlings at the proper level at the edge of the pond.
  • Different plants will tolerate different exposure to water, so this is something that you will need to experiment with.

Vegetables and Herbs that are Good to Grow In and Around Ponds:

  • Lettuce, Tomatoes, Basil, Spinach, Okra, Coriander, Cucumber, Red Salad Onion, Peas, Cauliflower, Cabbage, Eggplant, Parsley, Sweet Potato, Kohlrabi, Reddish, Turnips, Melons, Capsicum, etc.
  • Basil (Ocimum basilicum), Chamomile (Matricaria chamomilla), Hedgehog coneflower (Echinacea purpurea), Feverfew (Tanacetum parthenium), Johnny Jump-up (Viola tricolor), Parsley (Petroselinum crispum), etc.

Benefits of Pond Water Aquaponics:

  • Sustainable integrated aquaculture and food production –  The world population is increasing at the rate of 1.05% annually, and freshwater availability in every region of the world is decreasing day by day. Using the pond aquaponics technique, you are conserving water, and you can grow protein-rich fish and organic veggies simultaneously.
  • Increased productivity and efficiency – You can produce everyday food in your place, saving trips to the market and using the existing water at your home to create edibles. The plants growing in your pond system are also helping to take nutrients out of the pond water, which will decrease the unsightly algae growth in the pond.
  • Organic Food – The vegetables and fish in your pond are entirely under your control. You will be able to ensure that no chemicals or additives are in your water, so you will never need to question the quality of the food you produce. Be sure not to use chemicals anywhere in the watershed of the pond, and you are all set. Gowing your own organics will be very invigorating and will save you money. The prices of organic products are 100-600% higher than the inorganic ones. It could be a profitable business at the same time as you might be able to sell some of your edibles.

Water Conservation:

Pond aquaponics is a new technique in Olericulture in terms of the use of minimum water instead of flood irrigation. Water resource shrinkage is one of the major global issues. Pond aquaponics and wetland-associated food production are conserving the water and purifying the used water. 

Aesthetic Value and Monetary Opportunities:

Almost one century back, there were no supermarkets where fresh fruits, vegetables, or ornamentals were available for sale. Everybody was dependent upon the food they used to grow on their land, the climate was the healthiest, and the pollution was minimum. Pond aquaponics provides the same opportunity with the least effort.

Additional Benefits of Constructed Wetlands:

“Plants will clean the water to be used for other plants” this is the formula behind growing food crops in the constructed wetland filtration system in your garden. There will be no need to add fertilizers to your plants as the water will supply all they need. Constructed wetlands are the absolute best water filters that we can have for our pond. Using them to grow some veggies is a no-brainer.

Control of Soil-Borne Diseases:

Growing your veggies in your aquatic environment will remove the need for any pesticides or insecticides as there will be no soil-borne diseases to disturb your crop.

Closed-loop, Low Maintenance System:

A well-thought-out and constructed pond aquaponics system can be the ultimate closed-loop, low-maintenance growth system that you can find. Over time, with a bit of upfront experimentation, you can develop a system that pretty much takes care of itself other than planting and harvesting.

Research-Based Evidence Regarding Pond Aquaponics:

  • Experiment for Nitrogen Transformation in Aquaponics using the two plants: Tomato (Lycopersicon esculentum) and Pak-Choi (Brassica compestris subsp. Chinensis). The Nitrogen Utilization Efficiencies (NUE) of both plants were compared symmetrically. The tomato plant NUE was 41.3% (due to the higher root surface area), and that of Pak-Choi was 34.3%. The abundance of the Nitrifying Bacteria in Tomato-plant aquaponics was 4.2 folds higher than Pak-choi. The third parameter measured was water quality. The water quality of tomato-based AP was better. The contribution of the tomato-based aquaponics into the environment, in the form of N2O, was 1.5-1.9%, determining the potential anthropogenic (N2O emission into the atmospheric) ability of aquaponics. (Hu et al., 2015)
  • A 54 days experiment was conducted at the “AIT, Thailand” to determine the impact of pond-water filtration effect on the following:
    • Growth media: lettuce grown on sand media followed by gravel was found to have the highest yield and head weight compared with the control treatment.
    • Yield of Lettuce: the partially filtered pond water supports an 87% higher yield compared with that of unfiltered water. (Sikawa & Yakupitiyage, 2010)


Blidariu, F., & Grozea, A. (2011). Increasing the economical efficiency and sustainability of indoor fish farming by means of aquaponics-review. Scientific Papers Animal Science and Biotechnologies, 44(2), 1-8.

de Farias Lima, J., Duarte, S. S., Bastos, A. M., & Carvalho, T. (2019). Performance of an aquaponics system using constructed semi-dry wetland with lettuce (Lactuca sativa L.) on treating wastewater of culture of Amazon River shrimp (Macrobrachium amazonicum). Environmental science and pollution research, 26(13), 13476-13488.

Hu, Z., Lee, J. W., Chandran, K., Kim, S., Brotto, A. C., & Khanal, S. K. (2015). Effect of plant species on nitrogen recovery in aquaponics. Bioresource technology, 188, 92-98.

Palm, H. W., Knaus, U., Appelbaum, S., Goddek, S., Strauch, S. M., Vermeulen, T., . . . Kotzen, B. (2018). Towards commercial aquaponics: a review of systems, designs, scales, and nomenclature. Aquaculture International, 26(3), 813-842.

Pantanella, E. (2008). Pond aquaponics: new pathways to sustainable integrated aquaculture and agriculture. Aquaculture News, May.

Rakocy, J., Masser, M. P., & Losordo, T. (2016). Recirculating aquaculture tank production systems: aquaponics-integrating fish and plant culture.

Salam, M., Asadujjaman, M., & Rahman, M. (2013). Aquaponics for improving high-density fish pond water quality through raft and rack vegetable production. World Journal of Fish and Marine Sciences, 5(3), 251-256.

Sikawa, D. C., & Yakupitiyage, A. (2010). The hydroponic production of lettuce (Lactuca sativa L) by using hybrid catfish (Clarias macrocephalus× C. gariepinus) pond water: Potentials and constraints. Agricultural water management, 97(9), 1317-1325.

Somerville, C., Cohen, M., Pantanella, E., Stankus, A., & Lovatelli, A. (2014). Small-scale aquaponic food production: integrated fish and plant farming. FAO Fisheries and Aquaculture Technical Paper(589), I.

Aquatic Plant Functions and Types

No aquarium, pond, or water garden is complete without the presence of aquatic plants. However, picking the perfect water plants that fit your needs and preferences can be surprisingly tricky– especially for beginners.

There are many different aquatic plants (floating, submerged, emergent plants) to choose from, many of which have their own unique characteristics and habits. In short, there is no “one size fits all” plant species in selecting the best aquatic plants.

To help you get started, this article will cover just about everything you need to know about keeping water plants in your pond or water garden, including their different types, their functions, and how to best use them in your world of water.

What are Aquatic Plants?

white water lily

Photo from @stevenstph (IG)

Aquatic plants thrive in watery environments. Also known as hydrophytes or aquatic macrophytes, these plants vary widely in their ability to adapt to their surroundings. Some are entirely submerged, while others are partially submerged, and some float on the surface.

Most aquatic plants spread their fibrous roots through whatever debris and mud has accumulated at the bottom of their aquatic environment. Some of them can be free-floating on the surface, some are completely submerged and others just poke above the surface. They can be found in all types of aquatic environment and many are used to help us clean even our most polluted waters.

Popular examples of water plants are Anubias, African water fern plants, water purslane, and waterweed plants. Meanwhile, common aquatic flowers include lotus, mosaic flowers, water lilies, and water hawthorn plants.

In most cases, you will only have limited space in your water feature for aquatic plants, so it is very important to choose your plants wisely. Many can grow quite rapidly and will fill up their space quickly. You need to select each plant and its intended purpose carefully, whether to add vibrancy or color, add height, or control algae growth.

Choose a variety of aquatic plants for your water, to add texture and visual appeal, as well as to improve water quality. Most aquatic plants are quite hardy and require very little care from us.

General Characteristics of Aquatic Plants

Aquatic plants are excellently adapted to aquatic environments, including lakes, ponds, estuaries, marine lagoons, swamps, and river banks.

To adapt to their water habitat, these plants have common characteristics, which are listed below:

● Some aquatic plants have floating leaves on the water surface, whereas others emerge entirely above water. Some water plants are also submerged, meaning they grow entirely underwater. Some of these plants are free-floating and some have roots attached to the bottom soil.

● Plant cuticles limit water loss in most ordinary plants. Because aquatic plants live in water and aren’t threatened by water loss, most aquatic plants don’t need them. If they do, they have thin ones. They also have several stomata on either side of their leaves. As they don’t need to retain water, aquatic plants leave their stomata open most of the time.

● Because their stems are typically supported by water pressure, many aquatic plants have a less rigid structure. Their leaves generally appear flat on the surface because they must float. The air sacs in the leaves allow them to float.

● Their roots are typically small to allow water to flow into the leaves freely and are light and feathery because they don’t need to prop up or support the plants.

● Since they thrive in watery environments, their roots are specialized to take in oxygen. In the case of trees like swamp cypress, these water plants possess special roots (pneumatophores) to breathe. These roots stick out of the water surface to reach oxygen. Some aquatic plants, like duckweed, have an air-filled chamber under their leaves, allowing them to float.

● To adapt to swamps and waterlogged habitats, water plants can perform a biochemical process that helps prevent harmful chemicals from accumulating in low oxygen or anaerobic medium conditions.

Over the years, aquatic plants have adapted to cope with the many different water habitats that they grow in. Aquatic plants are the filters of our earths water and will continue to be long after we are gone.

Functions of Aquatic Plants

Apart from serving as an attractive centerpiece in water gardens or ponds, there are a many other functions of aquatic plants such as providing oxygen, food, and shelter to other organisms.

Let’s go into detail as to why water plants are so important:

Ecosystem Benefits

Aquatic plants provide many ecological benefits. For instance, they provide food and habitat for sea animals. Sea grasses are a food source for many commercial and recreational fishes.

This greenery also strengthens soil stability, preventing the erosion of shorelines in all varieties of water bodies. Many water plants are known to stabilize sediments, add oxygen to the surrounding water, and generate organic materials.

Water plants promote the diversity and function of aquatic systems (marine habitats and freshwater habitats). They produce oxygen and consume CO2 during the day, benefitting fishes and helping with filtration and pH stabilization. These plants also prevent unwanted algae growth by removing nitrates and phosphates from the water.

Underwater plants in coastal waters also foster a diversity of marine creatures. They act as a nursery, refuge, or foraging grounds for many sea species.

Water Clarity and Quality

Aquatic plants can improve the clarity and quality of a particular body of water. They also absorb nutrients that would typically cause nuisance algae blooms when left unchecked.

The finely divided leaves of most water plants act as a filtering system, trapping and settling particles from surface runoff, precipitation, and flowing water over land surface directly into streams. Many aquatic plants, such as bulrushes, are also great at absorbing and breaking down polluting chemicals.

To monitor the general health of a body of water or estuary, most professionals would also look into the condition of submerged aquatic vegetation. If the plants thrive and bloom, it is usually interpreted as a good sign.

Food Consumption

Several aquatic micro and macro invertebrates use the submerged sections of aquatic plants as a habitat. Fishes and other wildlife species consume these invertebrates as food, such as amphibians, reptiles, and ducks. The decomposition of aquatic plants by bacteria and fungi also provides food (detritus) for many aquatic animals.

Besides consumption by other underwater species, aquatic plants have also been a popular choice for human consumption. People around the world consume various edible species of algae. Most notably, Eastern Asian countries (Japan and Korea) have consumed macro-algae as a vegetable since ancient times.

One of the most popular algae is dried Porphyra, commonly called Nori (in Japan), Zicai (in China), and Gim (in Korea). This is extensively used to make sushi worldwide.

Other than nutritional benefits, some algae feature antibiotic, anti-inflammatory, and cytotoxic properties. Several water plants have also been pursued in the pharmaceutical industries.

Water Garden and Aquarium Design

Aquatic Plants and flowers also make for a great water garden design. They often become the center of attraction when added to a yard or garden– free-floating greenery could easily accent fountains, backyard, and indoor ponds, or aquariums.

In ponds or fish tanks, water plants give off oxygen, shade and hinder the unwelcomed growth of algae.

Water gardening and aquarium keeping, as a recreational activity, have seen a steady increase in several countries over the past decade. More garden hobbyists have been importing aquatic plants across the world for this reason.

Biomass Feedstock and Biofuel Generation

Recently, there has been growing interest in and many studies regarding using macro-algae to produce biodiesel because of their high oil yield. Many freshwater algae species have already been utilized for biofuel generation. There is also a growing interest in using freshwater plants, such as water hyacinth and giant Salvinia, as biomass sources to generate biofuels.

Other Uses

Aquatic plants (marine and freshwater) have extensive uses worldwide. They are utilized as compost, livestock fodder, fertilizer, and mulch.

Reportedly, several aquatic plants contain as much crude protein, crude fat, and mineral matter similar to conventional forage crops. Many also use aquatic plants as fodder to help improve the harvest. It is one of the best ways to remove nutrients from lakes dealing with artificial enrichment.

Aquatic plants are a vital part of any body of water. They provide food and shelter for other wildlife, improve water quality, and provide economic and aesthetic value to a property.

What are the Types of Aquatic Plants?

Aquatic plants differ significantly in type. These plants fall into four common categories: emergent plants, submerged plants, floating plants with leaves, and free-floating aquatic plants.

Please take note that the classification is primarily based on their root and leaf position.

Emergent Aquatic Plants

cattails in a pond

Photo from @mikebricklphotography (IG)

Emergent aquatic plants usually grow in shallow areas. They are often found along the banks of lakes or ponds. Emergent plants are resilient and can thrive on their own, even in varying water depths and availability.

Emergent water plants are often beneficial as a nutrient buffer since they can block or slow down unwarranted nutrients entering the pond. They can also stabilize shorelines and reduce erosion.

Below are some examples and information about common emergent aquatic plants:

  • Pickerel Rush: It is easy to find this plant in water garden stores selling aquatic plants. The Pickerel Rush has lovely purple flowers, which is excellent in improving the aesthetic of ponds and aquatic gardens. It will also block some runoff nutrients from entering the pond as well as absorb excess nutrients from the pond water.
  • Arrowhead: Arrowhead plants are also known as broadleaf arrowhead, lance-leaved arrowhead, or duck potato. This shallow aquatic weed has leaves that are notably shaped like an arrow. The leaves are mostly found above the water, but sometimes they may also be submerged or floating. It is an excellent aquatic plant to filter nutrients, but you need to monitor the plant to prevent overpopulation.
  • Bog Moss: This water plant commonly frequents wetlands or ponds in the form of creeping mats. It is a small, dark, and branched plant with spiral leaves on its stem. Its small flowers usually have three petals. Like other emergent water plants, it can also block runoff nutrients from entering a body of water.
  • Cattails: Also known as Tullies, Cattails are the most easily recognizable plant in and around bodies of water. Their spikey, sausage-shaped flowers called catkins appear atop their long, slender stems in late summer to early fall. This plant can be partially submerged and can be a vigorous grower with or without permanent standing water. They can grow up to 5 feet tall. Cattails also serve as cover for wildlife and a food source for aquatic rodents like Muskrats.
  • Water Primrose: Also called Pennywort, navelwort; many-flowered Pennywort, this plant has leaves that are round in shape and one inch in diameter. Its leaves are dark green colored and glossy, with scalloped edges. Erect stems happen during the plant’s flowering stage. They commonly bloom between April and September, depends on their species and location. In general, water primroses are considered highly desirable aquatic plants.
  • Maidencane: This is one of the many perennial grasses, and although they are familiar to sight, they can be somewhat hard to tell apart. Maidencane plants can measure up to 8 feet in height, with long, narrowly tapered leaves up to 12 inches long and 1 inch wide. This plant often forms dense colonies.
  • Purple Loosestrife: Commonly known as Lythrum, salicaire, or rainbow weed– the Purple Loosestrife is a herbaceous perennial plant. It measures up to 3 to 6 feet tall or more in width, given numerous erect stems from a woody root mass. Its stems take on a red-purple color and square shape. This plant can be quite invasive in or out of the water.
  • Spike Rush: The term spike rush can refer to any number of different types of spike shaped rushes with a terminal spike that grow in moist soil, marshes, shallow ponds, and wetlands. This plant can span many acres, serving as a cover for other wildlife. Some birds and animals also utilize certain species of Spike Rush as a food source.
  • Water Chestnut: This plant is commonly referred to as bull nut, water nut, or Trappa Natans. The Water chestnut is a rooted aquatic plant with a floating leafy rosette on the surface. Its stems can reach up to 16 feet tall, supporting two leaves. The submerged leaves are feathery and whorled along the stem.

The above listed plants are only a small sample of the many different emergent plants that can be used to beautify and clean out waters. Grouping varieties and using varying heights and textures can really give your pond or water garden a unique and beautiful look.

Be aware that many emergent plants grow quite vigorously and many are considered to be invasive or nuisance species.

Submerged Aquatic Plants

submerged plants in a pond

Photo from @cou_ntrylivingcreations (IG)

Submerged aquatic plants are entirely under the water, with a root system in the bottom sediment. However, minor sections may stick above the surface. These plants require water to support their structure physically.

Not all submerged aquatic plants are desirable. To weed out the undesirable varieties, it’s best to consider your personal preference, ecosystem balance, and the overall visual impact.

Some of the most common submerged water plants are listed below:

  • Common Waterweed: This branching plant has a long, slender stem with thick leaflets arranged in four whorls. The leaves are finely serrated and might be elliptical or linear in shape. It blooms with white flowers and yellow anthers. Like many other aquatic weeds, this plant needs to be kept under control to avoid taking over your water garden or pond.
  • Muskgrass: A form of erect algae, this is an excellent plant for ponds with excessive nutrients as it provides food and shade for fishes. While it may appear like several other aquatic plants, one defining feature would be in breaking its thin straw-like stem. Given this plant is a single-celled stem, the entire stem will turn flaccid once you break it. In comparison, other plants will simply either bend or break.
  • Pondweed: This thin-leaved aquatic plant is native to many areas. It has many benefits, such as being a food source, improving oxygen production, and it can be a refuge for other organisms in your pond or water garden. As a native plant, it is not as invasive as others, but it must still be kept in moderation. Some also confuse pondweed for a floating plant due to its surface leaves.
  • Bladderwort: This aquatic plant can thrive in ponds and environments with limited nutrients. Do note that this is actually a carnivorous plant. While it can initially look like an unorganized mess, the plants eventually form the starfish shape together. They will then shoot up yellow flowers. The Bladderwort can be a problem if it entirely takes over your pond. Given that this plant is not dependent on nutrients, it can spread rather quickly if left unattended.
  • Coontail: A submersed aquatic plant, the Coontail lacks any root structure. Its feathery and fan-shaped leaves are arranged in whorls that resemble the tail of a raccoon. This plant can grow up to 15 inches in height. It may also be found in deep water areas. If you’re planning to control the spread of your coontail, keep in mind that the process can be difficult as it is free-floating.
  • Tape-grass or Wild Celery: The moniker “wild celery” makes this plant sound like a regular celery you typically eat in a salad, but the tape-grass or wild celery only grows under the water. Like other aquatic plants, it also offers many benefits to other underwater species. Unfortunately, growing wild celery in your garden will not be possible. Its leaves appear like long ribbons and can measure up to 6 feet long. It’s also commonly referred to as freshwater eel grass.
  • Slender Water-nymph: This aquatic plant is typically found in clear, soft water lakes and ponds, most often in shallow waters. Notably, it has flexible, thread-like leaves, sheaths that are more or less rectangular, and 1 to 3 flowers in leaf axils. Its flowers are usually single in the axils along the branches and stem.
  • Pipewort: Pipewort is commonly found in shoreline water out to 3-foot depth. Take note that its minuscule size can make it challenging to pick out from among other sedges. Some native species are considered rare or endangered, but this aquatic plant is common within small ranges. Its leaves are linear or sword-shaped, and 2 to 3 flowers make up the flower head in silver, gray, or green colors.
  • Lake Quillwort: These herbaceous, spore-bearing plants have grassy spike-like leaves. Their rosette leaves have swollen bases, and sporangia with microspores and megaspores are found within the leaf bases. Most lake quillworts grow submerged as a rosette of linear leaves in freshwater all year. It is commonly found in soft water ponds, lakes, and slow-moving streams and rivers, in less than 2 feet of water. This plant is completely submerged, but it may be immersed near shorelines or stranded on land when water levels drop.

Some species of submerged aquatic plants are primarily used as ornamentals in outdoor water gardens and aquariums. Aside from aesthetic purposes, these water plants are also utilized as essential ecosystem components.

Floating Leaved Aquatic Plants

lotus in a pond

Photo from @itssarah_wilson (IG)

As the name suggests, floating leaf plants refer to rooted plants with most of their leaves drifting on the surface. A number of these plants have some rigidity; hence they may extend a little above the waterline. They are often rooted in the lake bottom and typically grow in protected areas with little wave action.

Here are some common examples of floating leaved aquatic plants:

  • Watershield: This aquatic plant is a small, football-shaped leaf that lies flat in surface water, such as ponds. Its size is 2-4 inches and has a dark red color underneath with a gelatinous covering. This native aquatic plant can kill off bacteria and algae and is also used as a hiding place for fish, making it one of the perfect habitats for some ponds.
  • American Lotus: The leaves of an American Lotus are almost perfectly round with no cleft. It may look completely flat on the water surface but may raise to 3 feet on a stalk. One of its defining factors is that it often has a yellow flower but may sometimes come in white or pink varieties. This aquatic plant also comes with an extensive root system called rhizomes.
  • Spatterdock: This aquatic plant is also known as “cow lily” and has a large heart or oval-shaped leaves. The floating leaves of the spatterdock are connected to a large stem attached to a spongy rhizome. It can grow to 1 foot long and 10 inches wide. Spatterdock also has a very noticeable half-opened yellow flower on the water surface. This flower is attached to a thick round stem which is about 6 feet long.
  • Fragrant Water Lily: The fragrant water lily is famous for its round-shaped leaves with a cleft extending to the center. Its size can range from 10 to 30 centimeters wide, while its color appears to be glossy green on the surface and red underneath. Another defining characteristic of this aquatic plant is its flower that it usually has broad petals and a pistil at the center packed with a bright yellow stamen. Lilies can come in many different colors and flower styles.
  • Yellow Floating Heart: This aquatic plant is considered a non-native invasive plant that originated from Europe and Asia. It has circular or heart-shaped leaves that are alternately arranged on the stem but opposite of the flower. The yellow floating heart is famous for its bright yellow flower with five petals at the top of the water surface. It also has a lot of flat-shaped seeds per capsule. It grows fast, shading out other native plants and causing damage to the aquatic environment by decreasing the oxygen level in the water and creating a suitable habitat for mosquitoes.
  • Floating Marsh-marigold: Considered a rare aquatic plant, the floating marsh marigold can be found in shallow, slow-moving water such as creeks, streams, sheltered lake margins, swamps, and beaver ponds. This plant usually roots in mud, silt, or clay, before spreading when stems root at the nodes. This distinctive aquatic plant has a resemblance to the larger common marsh marigold, which has yellow flowers. Typically, it has 2 to 6 small white flowers about 1 centimeter across, each with five petals.
  • Small White Water-lily: The small white water lily is another rare aquatic plant. It has up to 15 white petals and approximately 30 to 45 yellow stamens surrounding a saucer-shaped center disk. Its flowers are single-floating on the water’s surface, only closing up at night while opening up a few hours in a day. Expect to see this floating leaved aquatic plant in shallow, protected bays in lakes and slow-moving streams. They are also common in streams impounded by beaver dams.
  • Swamp Smartweed: Aquatic swamp smartweed has oblong leaves that are often flat with a blunt tip. They also have shorter, fatter flower clusters compared to their terrestrial form. Although there are several other smartweeds with pink-colored flower spikes, the Swamp Smartweed has the most shocking pink flowers of the lot. It makes them one of the most easily recognizable water flowers.

Some floating water plants will generally provide enough shade for underwater plants to survive beneath. These plants may serve as excellent fish and wildlife habitats. Take note that a healthy floating-leaved aquatic plant environment may dampen the waves, buffering the shore from the erosive effects of harsh weather conditions like storms and strong winds. Not only that, but they certainly enhance the aesthetic appeal of our ponds and lakes.

Free Floating Aquatic Plants

water hyacinth

Photo from @huichinhsu (IG)

True to their name, free-floating aquatic plants float freely on the water surface. Like many other water plants, they don’t grow their roots in the soil. Instead, the roots hang down into the water– making the rest of the plant buoyant like a raft. As they are suspended on the water, the plant can be moved around the water garden or pond surface by external factors like wind and strong water currents. These floating plants serve as decor to your backyard water property, plus they are also low-maintenance. Many of these plants only need to be thinned once a year to prevent overtaking the entire water system.

  • Mosquito Fern: The mosquito fern is often mistaken as duckweed. Mosquito fern is a free-floating aquatic plant with small leaves arranged opposite the stem. It consists of 2 lobes, the upper lobe floating above the surface and the lower lobe submerged under the water. Its name comes from its ability to fend off mosquitoes from laying eggs in the water. They usually grow on still or slow-moving water such as swamps, ponds, and lakes. Too many colonies of this plant may also decrease the oxygen level in the water for other organisms. Thus, it needs to be controlled before it covers the entire pond.
  • Water Hyacinth: Considered as another invasive free-floating plant, the water hyacinth grows in almost all freshwater environments. Its leaves are broadly round or elliptic and usually measure 15 centimeters with glossy green color. Its striking lavender-blue flower with yellow blotch consists of 6 petals, six stamens and measures around 5 centimeters. The fruit of the water hyacinth is a 3-celled capsule containing at least 50 seeds each. When not controlled, this plant may cause a variety of negative impacts in the freshwater. The dense, impenetrable mats that it can form cause waterways to clog, making water activities such as fishing and boating impossible. It can also blocks the air-water interface which can degrade the water quality.
  • Duckweed: Commonly found in still-moving ponds, lakes, and sloughs, the duckweed is an individual aquatic plant with an oval-shaped leaf only ¼ inch long. This aquatic plant grows fast and abundantly, making it an excellent food source for waterfowl and fish. However, the dense population of duckweed can be a nuisance for humans because they block the waterways. Recently, science and agriculture have made creative uses for the abundant amount of duckweed. They are usually harvested to eliminate pollutants and serve as feed to livestock and fertilizer for other crops. Meanwhile, researchers have tried to synthesize insulin by utilizing genetically modified duckweed.
  • Watermeal: Considered the smallest seed-bearing plant, the watermeal is a tiny elliptical-shaped aquatic plant measuring only 1 millimeter. Individually, it is hard to see them with the naked eye, but easier to see as it colonizes because they form large, green masses on the water surface. Commonly found in stagnant or still-moving water, this rootless plant is usually seen growing with duckweeds and mosquito ferns. Their fast-growing population can deplete the oxygen in the water quickly and may cause fishes and other respiring organisms to die.
  • Floating Crystalwort: This aquatic plant is a very popular aquarium plant in the US. It is commonly found in slow-moving ponds and streams. The submerged portion of the floating crystalwort serves as a suitable habitat for small invertebrates and becomes food for other amphibians and reptiles. The unique characteristic of the floating crystalwort is that its stem and leaves are almost identical. It is considered thick for its size and measures 0.08 inches wide. Despite the lack of function of its thin and colorless roots, they still help the floating crystalwort anchor in the mud.
  • Florida Mudmidget: Floating just beneath the water surface, this aquatic plant grows in rivers, lakes, ponds, and sloughs. This Florida native plant is considered another small duckweed. It has narrow, elongated fronds that connect to form colonies. The size of the fronds is only about 5 to 10 millimeters, with a tiny flower that is hard to see.
  • Giant Salvinia: This floating aquatic fern thrives in slow-moving, nutrient-rich freshwaters. It spreads aggressively and produces a floating canopy on the surface of lakes, rivers, and ponds. Through water currents, it is dispersed long distances within a waterbody or between water bodies with the help of animals and equipment like boats or vehicles. In some cases, the Giant Salvinia is cultivated by aquarium and pond owners and released through flooding or intentional dumping.
  • American Featherfoil: The American featherfoil is usually found in shallow, clear organic waters. It is an aquatic herb that has erect hollow and leafless flower stems. Each one grows a series of large, spongy, and air-filled flowering stalks. The air helps the plant stems buoy up above the water surface. However, it does not float much, given that its stem and roots anchor it firmly into place. It’s challenging to spot this plant in the water. To find it, look in shallow waters of ditches, ponds, and swamps without too much disturbance.
  • Water Cabbage: Also known as water lettuce, Nile cabbage, or shellflower, this free-floating plant has thick, soft leaves that resemble a rosette. It drifts on the water surface, with the roots hanging submersed beneath floating leaves. Notably, the water cabbage is one of the most productive freshwater water plants in the world. Its leaves can measure up to 14 centimeters long without a stem. They are also often utilized in tropical aquariums to serve as cover for fry and small fishes.

If you’re planning to include free-floating water plants into your large pond or an enclosed body of water– the greenery can easily make your man-made feature look more natural. However, some may be invasive, which can be harmful to the ecosystem in the long run. It’s your responsibility to keep all your aquatic plant species in check to strike a balance.

Frequently Asked Questions

What helps aquatic plants to float in water?

There is a particular tissue called Aerenchyma, which allows aquatic plants to float. The parenchyma cells form a network with air cavities that perform a gaseous exchange, making the plant light and buoyant, therefore allowing them to float in water.

Do aquatic plants have cuticles?

Most aquatic plants do not have nor need cuticles. The primary function of cuticles is to prevent water loss from plants. Since aquatic plants live directly in a well-watered environment, they do not need cuticles in any of their parts.

Do aquatic plants oxygenate water?

Yes, aquatic plants oxygenate the water and consume CO2 during the day, which helps the fishes and stabilize the pH level in the water.

What pond plants keep water clear?

Oxygenating pond plants such as Hornwort and Water Thyme are effective clear water plants feeding through their foliage and roots. Floating pond plants like water hyacinth and water lettuce are also good water filter plants because they feed heavily and grow fast. These plants also provide shade in the pond through their size by blocking the sunlight, which helps fight algae growth.

Can you have too many oxygenating aquatic plants in a pond?

Having too many oxygenating aquatic plants in a pond may cause the oxygen and pH levels to fluctuate. Aquatic plants consume oxygen at night, leaving little to no oxygen for other respiring organisms in the pond. For people with fish in their pond, not only does it lessen the oxygen in the water, but too many submerged oxygenated aquatic plants may also leave no room for your fish to swim around.

Final Thoughts

Aquatic plants are one of the best additions to your water garden or pond. Free-floating flowers and lush greenery could undoubtedly accent your fountains and grow right inside the basin.

Not only do they add aesthetic value, but they also help maintain your pond’s ecosystem and provide many benefits to your fish– though you will still need to manage their growth to prevent invasive species from overtaking the waters.

The aquatic plants included in this article are perfect even for a beginner, so here’s to hoping you’ll take what you’ve learned and put it to good use!

Aquatic Plants

Aquatic plants are equally beneficial for the pond water in which they are planted and the surrounding environment in which they are present. They provide oxygen to the pond fish, eliminate or absorb the excessive nutrients in the water, clean and clear the pond water, improve its aesthetics, and act as a shelter and food source for aquatic animals. 

All the Hydrophytes and Macrophytes (except Algae and Microphytes) are adapted to live in the saltwater or freshwater or on soil frequently saturated with water and are named “Aquatic Plants.” Macrophytes are the primary producers in the food chain, food source of some fish and wildlife. Aquatic plants such as submerged Macrophytes have particular morphological adaptations for living in water, and that is the “aerenchyma,” internal air packing cells.  

Different Types of Aquatic Plants based on Growth Habit:

The Depth and Duration of flooding decide which Aquatic Plant will survive in ponds, lakes, or rivers. The four different types of aquatic plants are mentioned below:

Emergent Plants:

The emergent vegetation roots into the water through its stiff stems and partially remain in the air because its leaves are adapted for photosynthesis more effectively in the air. Some examples of emergent aquatic plants and how they affect pond water quality is described below: 

  • Cyperus papyrus (paper reed, Nile grass): Suitable for shallow water ponds. It has a long history of multiple uses like papyrus paper (the first paper ever made), food for wildlife, ornamental plants, etc. They efficiently absorb nutrients such as Nitrogen and Phosphorus before being utilized by the nuisance algae. Therefore, they are preferred for constructed wetland filtration systems. 
  • Butomus umbillatus (Flowering rush): This emergent aquatic plant is becoming rare and needs to be conserved due to its remarkable phytoremediation properties.
  • Lythrum salicaria (purple loosestrife): It is equally adapted for water-saturated, shallow water, damp, and drier conditions, grown in wetland filters (CWFS) and around ponds as an ornamental plant. It is a medicinal herb used in the treatment of diarrhea and dysentery etc. 

Submerged Macrophytes:

submerged plants

As the name indicates, submerged plants grow underwater with roots attached to the pond bottom or without any root system. Some of the commonly grown submerged aquatic plants in ponds or constructed wetland filters are: 

  • Ceratophyllum demersum: this free-floating submerged plant is commonly called Coon-tail/Hornwort. This plant develops no root system and is a safe alternative to pond water purification. Its fluffy, spongy leaves provide comfortable cover for newly hatched fish. (Kulasekaran, Gopal, & John Alexander, 2014)
  • Myriophyllum alterniflorum: the “Watermilfoil” forms thick mats in and on the surface of water that interferes with the recreational activities of lakes, narrowing space for the juvenile fish in ponds, blocking the sunlight to penetrate into the water, utilizing the nutrients needed for fish to grow hence increase the competition. In short, it dominates in the ponds for both space and food. (Newroth, 1993)
  • Myriophyllum spicatum: named as “Eurasian watermilfoil” by local growers. It is native to Europe and Asia but widely grown as a pond plant in the US. Its capacity to grow from the broken offshoot parts makes it a problematic plant in the pond as it spreads rapidly to cover the pond space.
  • Hippuric Vulgaris: Mare’s tales, native to North America. It is an oxygenating aquatic plant widely grown in ponds for a clean, healthy pond (absorbs, creates a protected environment for fish and wildlife.
  • Echinodorus cordifolius (Mud-King, Creeping burhead): Native to Central and North America. It is widely grown all over the tropical and sub-tropical regions of the world due to its easy-to-grow and ammonia, nitrite, and nitrate removal characteristics. It can efficiently remove: 44.9-91.4% ammonia, 90.8-99.3% nitrite, and 55-89.75% nitrate. (Nakphet, Ritchie, & Kiriratnikom, 2017)  
  • Typha latifolia (Reed-mace, Bulrush, Cattail, Punks, etc.): is an aquatic to semi-aquatic flowering perennial herb. Typha is a good Phytoremediator plant widely planted around ponds or wetland filters. Its rhizomatic root system absorbs Fe (highest absorption), Mn, As, Zn, Cr, Cu, Ni, Cd, etc., very efficiently. (Salem, Laffray, Al-Ashoor, Ayadi, & Aleya, 2017)

Floating Leaved:

plants on the water
  • Nymphoides aquatic: commonly known as “banana plant or banana lily,” is the beauty of any pond, lake, or aquarium. Its growth rate is fast, efficiently absorbs the nutrients like nitrogen, phosphorus from the pond water acts as a water cleaner, and oxygenates the pond fish. 
  • Nymphoides pelatum: the yellow floating heart of the Menyanthaceae, blooms in June and continues to produce beautiful flowers throughout the summer. (Stuckey, 1973)
  • Potamogeton crispus: is an aquatic plant (Potamogetonaceae are collectively known as “pondweeds”) with either floating or submerged leaves. It is considered one of the crucial components of angiosperm’s food chain because of its importance as a food source for many aquatic animals and the habitat of water life.


water lettuce

Free-floating aquatic plants do not have roots anchored in the substrate or bottom of the water body. The various effects of free-floating aquatic plants on the quality of pond water and the habitat (in which they are growing) are mentioned below:

  • Salvinia minima (Floating Fern, Water Spangles): It grows on still waterways native to South America. It reproduces and spreads very quickly, forming a thick mat on the surface of pond water. Due to that, the amount of sunlight necessary for the growth of underwater plants decreased, ultimately decreasing the amount of Dissolved Oxygen in the pond water. (Dickinson & Miller, 1998)
  • Pistia stratiotes (Water lettuce or Nile Cabbage): It outcompetes algae for food in the water and prevents excessive algal blooms. It can produce bioethanol (at the rate of 0.14-0.17ethanol/g biomass) and contribute to cleaning the pond water. It also absorbs excessive nutrients, including N, P, etc. In constructed wetland filtration systems, water lettuce is planted for sewage wastewater treatment (proven to be the cheapest method of sewage water cleaning). (Soda, Mishima, Inoue, & Ike, 2013) 

The importance of using Native Aquatic Plants:

Native aquatic plant species help preserve biodiversity and a balanced water body. 

  • Easy to grow and maintain: native plants are well adapted to the local climatic fluctuations, water, and soil states. There is no need to create artificial conditions to grow them, synthetic pesticides to protect them, and no additional water requirements.
  • Fight with Unwanted Pond Weeds: By planting healthy native aquatic plants beds, you can minimize the space for the weeds to infest. Chinese tallow (Triadica sebifera), Alligator weed (Alternanthera philoxeroides), Torpedo-grass (Panicum repens L.), Tiny Water Spangles (Salvinia minima), Hydrilla (Hydrilla verticillata), etc. are some of the plague weed species of aquatic plants in ponds. 
  • Act as A Food Source for Aquatic Animals: forage fish, waterfowl, and aquatic invertebrates utilize native aquatic plants (seeds, flowers, stems, and fruit sometimes) as a food source. 
  • Help improve water quality: a diverse combination of emergent, submerged, and floating plants means you have collected a variety of excessive nutrient absorbents at one place. They produce oxygen, absorbs the carbon dioxide and other gases produced by either fish or present in the air, at the same time hold the pollutants in their roots, stems, or leaves, and ultimately clean the pond water. 

The US native aquatic plants (suitable for all kinds of ponds, either shallow or natural earth bottom-ponds, etc.) are mentioned below:

  • Thalia dealbata, 
  • Golden Club,
  • Sagittaria Latifolia, 
  • Pickerel Cordata, 
  • Variegated Water Celery, 
  • White Calla Lilly, 
  • Canna Cleopatra, 
  • Canna Orange Punch, 
  • Blue Flag Iris, 
  • The locally available varieties are Louisiana Iris (Fortune Finder, Colorific, Red Velvet Elvis, Red-mood, Black Gamecock, etc.)

Ornamental aquatic plants:

  • Ludwigia Sedoides (Mosaic Flower): it produces diamond-shaped leaves, thus named as mosaic flower. It has beautiful reddish-green leaves with reddish-pink shoots.
  • Myosotis scorpioides (water forget-me-not): is an introduced species to North America, happily grow in ponds, bogs, swamps, etc.
  • Cyperus alternifolius (Umbrella palm): it poses an elegant look in your pond by creating a soft backdrop for the smaller plants (its height goes up to 6 feet).
  • Nelumbo nucifera (water lotus): you can name it “the beauty of pond” because of its soft-colored pinkish flowers that demand attraction from the viewers.
  • Pontederia cordata (Pickerel pond plants): it produces beautiful ornamental purplish flowers, and the bloom is long-lasting. 
  • Lobelia cardinalis (cardinal flower): native to Eastern and Western US, prefers the partial shady conditions, produced red-colored flowers. It is considered perennial, but it may be short-lived and has medicinal importance too. 
  • Iris spuria (Blue Iris): the beautiful blue iris is the first to bloom in the spring. The genus “Iris” comprises hundreds of irises that have aquatic habitats.
  • Acorus calamus (sweet flag): is an emergent to partially submerged aquatic pond plant. It is easy to grow and maintain kind of plant. It adds a bright, colorful spot in your pond with its light green leaves having yellow strips.
  • Colocasia esculenta (Taro pond plant): a plant always makes a distinguished appearance in the pond is the Taro plant. This impressive water lover produced corms that are eatable. Taro plant has been planted for its phytoextraction properties in wetlands and ponds. (Madera-Parra, Peña-Salamanca, Peña, Rousseau, & Lens, 2015)
  • Pontederia crassipes (water hyacinth): is a free-floating aquatic plant known for its fast-growing and eye-catchy flower colors. Water hyacinth has been studied a lot for its distinguishing phytoremediation properties. It is planted in constructed wetland filtration systems and ponds for the cleaning of kitchen wastewater as well as to reuse the pond water. (Parwin & Karar Paul, 2019)

The careful use of native aquatic plants in a body of water is the absolute best way to control water quality. Humans have been devising and developing many different types of ingenious and environmentally costly gadgets and poisonous chemicals in an attempt to artificially control water quality. The truth is and has always been that using aquatic plants and working on the side of Mother Nature is now and has always been the answer to healthy and clean water.


Dickinson, M. B., & Miller, T. E. (1998). Competition among small, free-floating, aquatic plants. The American midland naturalist, 140(1), 55-67.

Kulasekaran, A., Gopal, A., & John Alexander, J. (2014). A study on the removal efficiency of organic load and some nutrients from sewage by Ceratophyllum demersum. L J. Mater. Environ. Sci, 5(3), 859-864.

Madera-Parra, C., Peña-Salamanca, E., Peña, M., Rousseau, D., & Lens, P. (2015). Phytoremediation of landfill leachate with Colocasia esculenta, Gynerium sagittatum, and Heliconia psittacorum in constructed wetlands. International journal of phytoremediation, 17(1), 16-24.

Nakphet, S., Ritchie, R. J., & Kiriratnikom, S. (2017). Aquatic plants for bioremediation in red hybrid tilapia (Oreochromis niloticus× Oreochromis mossambicus) recirculating aquaculture. Aquaculture International, 25(2), 619-633.

Newroth, P. R. (1993). Application of aquatic vegetation identification, documentation, and mapping in Eurasian watermilfoil control projects. Lake and Reservoir Management, 7(2), 185-196.

Parwin, R., & Karar Paul, K. (2019). Phytoremediation of kitchen wastewater using Eichhornia crassipes. Journal of Environmental Engineering, 145(6), 04019023.

Salem, Z. B., Laffray, X., Al-Ashoor, A., Ayadi, H., & Aleya, L. (2017). Metals and metalloid bioconcentrations in the tissues of Typha latifolia grown in the four interconnected ponds of a domestic landfill site. Journal of Environmental Sciences, 54, 56-68.

Soda, S., Mishima, D., Inoue, D., & Ike, M. (2013). A co-beneficial system using aquatic plants: bioethanol production from free-floating aquatic plants used for water purification. Water science and technology, 67(11), 2637-2644.

Stuckey, R. L. (1973). The introduction and distribution of Nymphoides peltatum (Menyanthaceae) in North America. Bartonia(42), 14-23.

Wetland Filtration

Any area that is wet either due to a rainstorm or industrial/sewage discharge would not be considered a wetland. A Natural wetland is unique in that plants grow in it, animals live here, processes take place within that flooded water, and an ecosystem thrives. Wetland filtration, whether natural or manmade is a powerful water treatment solution.

Wetland Classification

  • Bog: or a bogland is characterized with the deposition of Peat (partially decayed organic matter or vegetation, covers large areas in the form of peatlands, mires, or moors) and Mosses (also called Bryophytes, are the small, usually one cell thick, flower-less plants, developed in the form of mats in damp shady places)
  • Fens: are pH neutral/alkaline, mineral-rich wetlands fed by either surface or groundwater. A fen is different from other wetlands because of its unique water chemistry, which maintains a stable water table year-round. Carnivorous plants (e.g., Butterworts “Pinguicula” use granular, sticky substances to entrap, lure the insects), Sedges, Brown Mosses are the dominant vegetation of Fen.
  • Swamps: are forested wetlands that are constantly flooded with nearby streaming water bodies and are dominated by water-loving trees, shrubs, bushes, herbaceous plants. The vegetation is so dense that when the water (maybe groundwater, precipitation, or tides) flows down through the roots, all the pollutants, nutrients (mainly P and N, either buried in the saturated soils or accumulated at the bottom of the swamp), and sediments are naturally filtered out.
  • Marsh: forms a transition between aquatic and terrestrial ecosystems as present at the edges of lakes or streams. Marshes are dominated by herbaceous vegetation (grasses, reeds, or rushes) and not woody plants. Papyrus (Cyperus papyrus), Cattail, Sawgrasses (Cladium spp.), and sedges are dominant among vegetation well-adapted for marshy wetlands.

Wetlands are an essential part of any ecosystem that offers habitats for many migrating birds, mammals (both small (minks, reptiles) and large (moose, etc.).), plants, and insects.

Wetlands are typically teeming with wildlife due to their diverse ecosystem and the fact that humans don’t usually frequent wetlands.

The Wetlands are the areas flooded with water, either permanently or temporarily that support aquatic plants and animal growth. Wetlands are beneficial for the area where they are present because they are involved in water purification, removal of nutrients from contaminated water, and water storage.

How do Natural Wetlands Work?

The water that enters any NW may be surface runoff from residential homes and lawns(fertilizers, pet waste, sewer, and septic), commercial hard surfaces (industrial waste, road salt, petroleum), agricultural land (livestock waste, chemical pesticides, and fertilizers) or direct sources such as streams, rainfall, and tides. All of which may contain large quantities of nutrients, suspended solids, chemicals, and pathogens.

Through the dense vegetation of NW, water moves slowly, settling down the sediments and suspended solids while the plants and microorganisms absorb nutrients. Gases like CO2 and other harmful gases are stored in sinks in wetlands. This is a wonderfully natural purification process that occurs in NW without us investing any energy and cost. We just need to stay out of their way.

Benefits and Uses of Natural Wetland Filtration

Flood Control and Water Storage

The continuous rains and snow-melting processes are the causes of floods. The wetlands (either Natural or Constructed) near the water-heads of rivers or streams play an important role in slowing down that water’s runoff and helping control damaging floods. The Natural Wetlands store back the water in its spongy sedimentation layers and release it during the drought periods. In this way, life in the wetlands survives during water scarcity periods due to stored water.

Heavy Metal’s Traps

The NaturalWetlands came into being through flooded water, rainwater, or runoff water. This water contains many nutrients (excessive Nitrogen, Carbon Dioxide, Phosphorus, and heavy metals). These nutrients get stored in the sediments or plant’s bodies and remain stored until plants die, are harvested by the animals, or microbial processes convert these elements into a gaseous form released into the atmosphere. If these natural nutrient absorbents would not be present, no one could be able to protect his/her land from that soil desolating water.

Water Purification

The animal and plant population in the wetlands helps absorb, utilize and decompose the water contaminants. Water-loving animals such as Oysters filter more than 200 Liters of water every day, searching for food. Water Hyacinths, Reed-grass, duckweed, and Cattail plants remove Iron, Copper, Mercury, and pathogens from the water and store them in their body or convert them into less toxic forms.

Check out our article on Phytoremediation.

A Balanced Ecosystem

They help bring a balance to the environment. The Natural Wetlands Control flood water by acting as a sponge to store excessive, un-wanted water and use it later during shortage periods. Loss of wetlands means the loss of many wetland animals and plant species and natural water filters, which causes an imbalance in the atmospheric conditions, flood peaks, and soil erosion.

Natural Predators

Wetlands not only filter nutrients from water but also reduce the mosquito population. It contains many insects, amphibians, and birds that act as natural predators for the mosquitos.

Biodiversity Nurturing

Aquatic plants and grasses of wetlands are part of large mammals’ diet, for example, cows, goats, deer, moose, etc. The birds dive into the shallow shorelines and capture small insects, which helps maintain a balance in the population of insects in the wetlands. Wetlands are the breeding grounds of many birds (Ducks, Geese, Cranes, Herons, Shorebirds, and Blackbirds, etc.); they are also excellent midday resting and hiding places for countless other creatures, both large and small.

Constructed Wetland Filtration System

We have constructed wetlands to act as Biofilters similar to that of Natural Wetlands to treat rainwater, groundwater, greywater, municipal water, and reclamation of mining-affected soils. Biological and Mechanical filters, Plants, and Sand/Gravel are collectively used in the backyards of houses and many industries to clean the water again and again, just like a natural wetland.

The big difference between a natural and a constructed wetland filtration system is that the NW are provided to us by nature and will not be found in cities or town centers, while CW can be created in small areas of the garden, back yard, landscapes, city lots, rooftops, commercial sites or just about anywhere. While the role of both is the same, i.e., the wastewater treatment and pollution control, we have the ability to greatly increase our water clarifying ability through the use of CW.

How Constructed Wetlands Work to Clean the Wastewater

A constructed wetland is a human-designed shallow wetland of varying sizes with different kinds of layering (sand, gravel, rocks) and wetland plant species growing in it. Wastewater flows from one end of CW or is pumped into the bottom, passes through the sub-surface/surface, and finally pours out at the other end, having been cleaned.

The system typically keeps the water just above the plant roots. The aquatic plant masses, especially the Reed-grass species, act as active reaction regions (with the help of microorganisms, complex physiochemical and biological reactions) and absorb N, P, pathogens, and other contaminants from the water.

Another advantage of constructed wetlands is that they allow for the settling out of sediment and sludge, which would otherwise end up in our pond and streams.

Components of Constructed Wetlands

There are many different styles and types of constructed wetlands. Different types have different applications, but many contain the same components.

  • A Geomembrane lining (synthetic polymer, very low permeability)
  • Concrete or clay lining (to protect the surrounding water table)
  • The substrate (gravel, rock, stone, sand) depending upon availability.
  • Water flow

Types of Constructed Wetlands

Surface Flow

As the name implies, the surface flow system is installed in the ground so that the water flows across the wetland’s surface. Surface flow wetlands are used to treat wastewater by settling down the particles, removing/destroying the pathogens, extracting nutrients using plants and other organisms living on the plants.

The UV irradiation kills pathogens, and sedimentation occurs as the wastewater flows slowly through the wetland. The below water soil layer is anaerobic while the plants’ roots provide oxygen, which allows the overall initiation of complex chemical and biological reactions to remove the nutrients.

Specifications of Surface Flow Wetland Filtration System:

  • A surface-flow system always has a Horizontal flow of water across the plant’s roots and never vertical.
  • It requires a large area for proper installment and functioning. These systems are also named “Waste Stabilization Ponds” because they work the same way as waste stabilization lagoons.
  • The treated water can be used for irrigation purposes or returned to the surface water.
  • The system is less efficient in the winter because of the decreased intensity of sunlight and temperature, both of which are important in the treatment processes.
  • The system is best suited for Tropical and Subtropical climates because of the constant availability of bright sunlight and high temperature but does provide value in almost any climate.
  • Due to the open water availability, the surface system may be used by aquatic animals.
  • The plants encouraged to grow in a surface flow filtration system are Pickerel-weed (Pontederia cordata), Common Water Hyacinth (Eichhornia crassipes), Broad-leaf Cattail (Typha latifolia), and Common Reed (Phragmites australis).

Subsurface Flow

The subsurface flow filtration system is installed similarly to the surface flow, but the water flows through the plants’ substrate and roots rather than across the surface.

Specifications of a subsurface flow system:

  • It is a more efficient system as the flow of water through the substrate and plant roots allows for more efficient water treatment than water flowing across the surface.
  • A subsurface flow may be horizontal or vertical. The vertical flow constructed wetland is the type most often used for treating pond water on backyard ponds and commercial and industrial retention ponds.
  • If used for wastewater treatment specifically, the subsurface system does the secondary wastewater treatment, i.e., the water has already passed through the primary treatment processes like a compost filter and settling area. After that, the working of the subsurface flow system starts.
  • The system does filtration, adsorption, and biodegradation. After passing through all the processing compartments, the treated wastewater will be safe enough for surface discharge or irrigation.
  • The plants encouraged to grow in a subsurface filtration system are:
    • Reed-grasses (the grasses build up reed-beds (considerable litter layer) that is helpful in pollutant removal from greywater)
    • Bul-Rush or Cattail (Scirpoides holoschoenus)
    • Soft Rush (Juncus effusus)
    • Musa spp.
    • Sedges (belongs to Carex, species-rich genus, similar to grasses).

Types of Filters in Constructed Wetlands:

Constructed wetland filters work as a natural filter to purify sewage, industrial, and runoff wastewater and cleaner water filtration such as pond or lake filtration. The system receives water and pushes it upward. The water passes through stones, gravel, and plant roots. These screens act as filters to remove nutrients, pollutants, etc. this is the most economical and ecologically beneficial method for the primary treatment of wastewater in small communities. There is no use of chemicals to clean the water; instead, the beneficial bacteria on the rocks, plant roots (Rhizofilteration: removal of contaminants from the water through a mass of roots) are the sources for pond water filtration.

Vertical up-flow constructed wetland filter:

Up-flow wetland filters are available in different shapes and sizes for small and medium to large scale pond installations. The working science behind all the up-flow filters is that the water is pumped into the bottom of the filter and then flows upward through certain filter media (will be different for different filters but mostly sand and gravel) to remove suspended solids. Then proceeds through the plant roots for further filtration through a combination of biological processes that remove the nutrients and pollutants. The water then flows back into the pond through a waterfall or stream, which provides more aeration and oxygenation of the water.

It is also suitable for the filtration of highly polluted water if designed for a longer percolation duration to increase the wastewater processing time.


  • A sedimentation tank (used for the settling of large solids to prevent clogging the filter)
  • A layered filter package (acts as a biochemical reactor).
    • Large to medium-sized stones at the bottom
    • Above it is a layer of smaller gravel
    • A layer of sand on top of the rock (in some applications)
    • Planted in the top layer are varieties of aquatic plants (microorganisms are present at the root of the plant, absorbing the nutrients from the water to grow).

Water from the sedimentation tank is pumped into the distribution tank. Then water moves through the reed plant’s roots to the bottom of the filter package. The bacteria present at the roots absorb the water’s nutrients, making it clean and clear.

This water cleaning system is available to install at a small scale for a garden, lawn, pond water treatment and large-scale sewage wastewater treatment, industrial water treatment, etc.

Horizontal flow constructed wetland filter:

It is the ideal filtration system for home gardening as it filters light to moderately polluted water. Almost 30 years ago, no one could think that they might need a filtration system to clean even their house water! Water pollution has been increased in the last few decades while the plants have stayed the same.

There are many varieties of wonderful plants that can help us to clean our water.


  • Water reservoir for settling (if filtering water with high levels of suspended solids)
  • Gravel and sand-filled basin
  • Reed grass or any other wetland species, e.g., Indian Lotus, Eel-grasses, Seagrasses, etc.

There is no need to pump the water as it flows with the force of gravity. The water from the tank flows towards the filters (gravel, sand, plant roots) horizontally. Significant removal of pathogens by aerobic decomposition, reduction of nutrient concentrations, reduced BOD of wastewater are the functional characteristics of a subsurface horizontal wetland filtration system.

Flow field filtration system:

The flow field is the preferable system that cleans large quantities of water compared with the above-described systems. A shallow trench (30-80 cm depth) is constructed, the water flows through this swale, the swamp vegetation planted in that trench cleans the running water through a number of chemical (either change the water nutrients concentrations to make them suitable for the soil) and biological processes (bacteria absorbs both the oxygen, Nitrogen and heavy metals from the wastewater).

The whole filtration system converts the unsuitable water into standard usable water. Again, the system can be installed for small and large-scale wastewater treatment and is often used to treat parking lot runoff.

The Benefits of constructed wetland’s filtration system

Nitrogen removal:

Nitrogen, in the form of Ammonia, Organic Nitrogen, Nitrate, Nitrite, and ammonium, is the chief element present in wastewater. Why is it important to remove Nitrogen when it is essential for plant growth? The answer is that not all the forms and excessive concentrations of Nitrogen are good for aquatic plants, animals, and soil. So it is important to either alter or remove excessive N before discharging the water.

  • Nitrification: Ammonia in the water is converted into Ammonium ions,
  • The Bacterium Nitrosomonas sp. aerobically convert Ammonium ion into Nitrite,
  • Nitrobacter sp. Changes the Nitrite into Nitrate,
  • Denitrification: Nitrate is then reduced (anaerobically) into harmless Nitrogen gas and released into the atmosphere.

Phosphorus removal:

Increased use of chemicals in the form of dyes, fertilizers, pesticides, LEDs, and safety matches, has also increased the P-pollution in water. Otherwise, P is in short supply under natural undisturbed conditions. It is not easy to remove P from water as it does not have an atmospheric component like Nitrogen.

The aquatic plants grown in wetlands absorb the P from water (it is an essential factor in any plant’s growth and development). The living biomass is then removed once their growth cycles are completed (have absorbed the maximum P they could) and replaced by new plants for the efficient removal of P. This is done for heavily contaminated water treatment. When treating pond water, simply removing the plants’ foliage and not allowing them to decompose back into the water will remove much of the phosphorous.

Pathogen removal:

Constructed wetland filters remove pathogens present in water. The sub-surface wetland removes the pathogens (Bacteria, Viruses, Protozoa, and Helminths) more efficiently than surface wetlands.

A sub-surface flow wetland removes:

  • 90-99.9% Bacteria
  • 90-99% Viruses
  • 90-99% Protozoa
  • 99% Helminths

A surface flow wetland efficiently removes:

  • 90-99% Bacteria
  • 90-92% Viruses
  • 90% Protozoa
  • 90-99%% Helminths

Source: Maiga, Y., von Sperling, M., Mihelcic, J. 2017. Constructed Wetlands. In: J.B. Rose and B. Jiménez-Cisneros, (eds) Global Water Pathogens Project. (C. Haas, J.R. Mihelcic and M.E. Verbyla) (eds) Part 4 Management Of Risk from Excreta and Wastewater) Michigan State University, E. Lansing, MI, UNESCO. Material was copied from this source, which is available under a Creative Commons Attribution-ShareAlike 3.0 Unported license.

Flood water retention:

When used for flood water retention, the wetland filters are installed in a retention area to allow for water accumulation, settling, and soaking back into the groundwater. They receive the water during surface runoff, storms, or floods. CW’s thick vegetation slows down the speed of flowing water, hence controlling the drastic effects of sudden, un-planned water deluge. Nowadays, CW’s are being established around industries and cities to protect the high-priced commodities from flood damages and clean the wastewater discharged by the industries.

An example of this is NIMR WATER TREATMENT PLANT, in Oman (consisted of 780hc of wetlands and large ponds) to clean the wastewater (115,000m3/day) discharged by the nearby oil industries.

Research-Based Accepted Facts About CW:

Construction of wetland filtration system for a small community:

In 2009, an experiment was conducted at the village of Ileydagi, Turkey, situated near Lake Egirdir, to check out the rate of removal of contaminants from the constructed wetland system. The system was further assisted with BSF (Buried Sand Filtration system) and BSSF-CW (Buried Sub-surface Flow Constructed Wetlands). After fourteen months of observation, it was concluded that the system removes:

  • 97% of BOD (Biological Oxygen Demand)
  • 85% of total Nitrogen
  • 69% of TP (total Phosphorus)

Whenever you go for an environment-friendly system to protect the soil, water, and air from further pollution, you have to engage the local people. Water pollution, lowering groundwater levels, and water shortage are the burning issues of every city, town, and country. We must all spread the word to make our friends and neighbors understand the wetlands’ benefits.

Sub-Surface Constructed Wetland for Single House Wastewater Treatment:

In Eastern Norway, subsurface, constructed wetland systems were separately installed in single houses to clean the sewage wastewater.

The system contains the following filters:

  • A septic tank: collecting and passing the wastewater to the bio-filter.
  • Aerobic Bio-filter: to remove organic waste and also for denitrification
  • Upflow saturated filter: remove P, microorganisms, and polishing the sewage water.
  • Upflow filter media: contains the finest sand at the top, coarsest in the middle, and gravel at the bottom (kept in fixed positions)

The system was installed for five years without any maintenance necessities. After three years of successful operation, the average values/day measured were:

  • N: 30%
  • P: 99.4%
  • SS: 70.8%
  • BOD: 97.8%
  • Zero Escherichia Coli/Coliphages

The treated water was tested to be beneficial for irrigation, soil, and the ecosystem as the excessive nutrients, organic matter, and pathogens have been removed.


As humans destroy more and more of the natural environment on this earth, we must be aware that the reduction of plant material covering this earth is not without consequences. Through the application of constructed wetland filters and re-constructing damaged or once filled wetlands, we can begin to turn the tide the other way. By coupling the efforts of wetland creation, permaculture, and the aggressive planting of trees and plants on every bare surface possible, we have a chance to save this earth and bring the earth’s natural ecosystem back into balance.

When it comes down to it, it’s not about hard-to-understand scientific principles or complex, hard-to-implement procedures; it’s really all about plants. We need more. Wouldn’t a healthy earth with a naturally balanced ecosystem be a lovely gift to leave your grandchildren?


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Windmill Pond Aeration a Comprehensive Not-so-breezy Guide

windmill for pond aeration

Windmill pond aeration is the best solution to improve the quality of water in your rural pond. Simply put, water needs oxygen to keep ponds clean and preserve ecosystem equilibrium. We’ll explain how windmill pond aeration works, why you’ll benefit from it, its pros and cons, and some things to keep in mind when getting one. 

This article will tell you important information about these energy-efficient means of pond aeration. We can say you’ll be blown away by the things you learn here!

Why You Need Windmill Pond Aeration

Oxygen is a natural cleaner— the key ingredient in maintaining water quality. To further explain: An oxygen-rich pond is more capable of getting rid of waste. The pond’s waste contains “deposits” from animals, such as fish and geese, and additional waste material that comes from stormwater runoff and animals and plants that perish in the pond. When it comes to breaking down waste and bringing it into solution, aerobic bacteria (oxygen-utilizing bacteria) perform almost 20 times faster than anaerobic bacteria. These broken down wastes can be flushed out or used to grow new life while in solution.

This maintenance system is operational all year round and provides your pond with a continuous oxygen supply.

During summer, oxygen is supplied by surface winds. However, these winds supply only the upper part of the water with oxygen. What happens is that the water separates into two layers and the lower layer remains suffocated.

The rising air bubbles of a bottom aeration system effectively move the water to the top. By aerating the pond’s bottom during the winter period, you allow continuous circulation and maintain a level of oxygenation that ensures fresh water all year round. 

Windmill aeration is a cost-effective solution for providing bottom aeration to your natural bottomed, large pond, which will significantly improve your pond’s water quality.

Aeration will be beneficial to all ponds. Since all aquatic life use dissolved oxygen in surface water, oxygen levels are commonly used to determine the “health” of ponds.

What is Windmill Pond Aeration?

Windmill pond aerators can be your way of letting nature do all the work of aerating, circulating, and destratifying your pond.

Wind-powered aerators take the place of electric aerators, which can cost anything from thirty to fifty bucks a month to run. These windmills will pay for themselves in just a few years, and these are ideal for aerating faraway ponds without access to electricity!

Windmill aeration adds oxygen to all of the water, including the bottom. This is very important because once the lake has oxygen near the bottom, new larvae of insects, snails, fish, and beneficial bacteria can start living there.

For the past 20 years or so, the most typical windmill tower has been a three-legged, twenty-foot, galvanized metal structure. A 20-foot windmill’s average footprint varies between 84 and 100 inches, based on the specific model bought.

There are also four-legged windmills, such as the Outdoor Water Solutions Windmills and Mescan Windmills, that include a square-based footprint of varying sizes depending on the height required.

How Do Windmill Pond Aerators Work?

Bottom aeration is achieved simply by using air compression through an airline connected to an aeration diffuser at the pond’s bottom. The production of air bubbles at the bottom releases oxygen that moves the water from the deepest part of the reservoir up into the atmosphere.

Therefore, the large volume of water moved to the surface by increasing air bubbles makes the water remove toxic gases from the atmosphere, and the water picks up more oxygen while it is on the surface. Aeration accelerates the process of oxidation or burning of pollution in the water. The result is fresh, clear, and bright water with a sweet aroma that supports the abundant life of fish and eliminates algae and excessive weeds.

What Are the Types of Pond Aerators?

How else can you introduce dissolved oxygen into a pond? Some ways to do that are through wind, mechanical aeration, and diffused aeration.

The type of aeration used in a pond will directly impact the pond treatment process. What mixture of aeration methods depends on the form of a pond, organic loadings, surface area, and depth.

  • Wind-driven surface aeration: when a breeze blows over the pond, oxygen is dissolved into it. This is a natural, small-scale version of mechanical agitation systems.
  • Mechanical aeration systems disturb the water surface, making spray and waves, allowing oxygen from the air to be captured into the pond. Surface fountains, paddle wheels, and rotating brushes are examples of such mechanical machines.
  • Diffused aeration is when a blower system is used to disperse air through the water. Fine bubbles are formed in the air stream; the smaller the bubbles, the more oxygen is transferred.

Solar Power vs. Wind Power for Aeration

Both wind and solar power are excellent choices for pond keepers trying to save bucks in the long run or if a remote water garden needs aeration. Despite both being renewable energy sources, their aeration capacity is not always comparable.

Solar energy, for example, is a much more readily available renewable energy source that is often less costly and simpler to install for standard garden ponds. Unlike the wind, which can be uncertain, you can usually rely on at least a little sunlight every day as long as trees don’t shade your solar panels.

If you don’t need a lot of aeration, a good solar-powered aerator might be a better choice than wind power.

Wind-powered aerators are unmatched in airflow vs. energy efficiency if you have a massive pond in a remote area. The top-of-the-line models can easily offer aeration at least six CFM suitable for ponds greater than 30,000 gallons or bodies of water larger than 1 acre.

You’d have to buy a much larger solar panel (which will set you back a great deal of money) to get something close to this level of CFM with solar power.

Not only that, but top-of-the-line solar panels also necessitate specialized repairs if they have problems, leaving you without aeration until you can hire a professional.

In contrast, you can easily manage windmills with a bit of DIY and a manufacturer’s extended warranty for repairs.

Advantages of Windmill Pond Aerators

Cost-effective, Renewable Energy

Wind power, like solar power, is an environmentally sustainable and green energy source that allows you to be entirely off the grid. You won’t need a power supply (electrical outlet), and the only expense would be the original buying price, which will save you a lot of money in the long run.

Getting Rid of Algae

Aeration reduces algae growth by removing their food (nutrients), nitrogen, ammonia, and soluble phosphates from the surface and out of the pond. Iron and manganese oxidize and leave the solution at the pond’s bottom. Once the oxidation of these metals begins, they no longer dissolve again. 

Aeration increases aerobic bacteria that consume the other nutrients that algae and weeds need to grow. Aerobic bacteria eat these foods before weeds and algae can, forcing them to starve and die.

Aerobic bacteria are the good guys: they breathe in oxygen and breathe out CO2 like us. They have a massive appetite for devouring any organic item. Aerobic bacteria begin to eat the organic sediment at the bottom of the pond and continue to eat as long as they are given oxygen. 

The more aeration in the winter, the fewer algae in the summer.

Removes Unwanted Waste and Odors From the Pond

Aeration also removes ammonia, hydrogen nitrate and sulfide gases, and foul odors from the pond. These chemical compounds are the byproducts of natural biochemical processes in living organisms.

Potential for Massive Aeration (Airflow)

Wind-driven aerators are highly suited for generating a good amount of airflow, which can oxygenate waters ranging from one to twelve acres. Smaller aerators can oxygenate koi ponds in the garden, while higher-end models can aerate even the most extensive natural ponds.

It’s possible to install it in a remote area.

Windmill aerators can be positioned entirely off the grid—in fact; they work optimally in this setting. 

You’ll need as much exposure to air currents and as much height as possible to get the most power out of your windmill. This requires minimum obstructions—two aspects that a remote installation will always offer.

Disadvantages of Windmill Pond Aerators

It can be unsightly in your landscape.

Windmills will undoubtedly stick out in your landscape, especially if the area is small. Be prepared for a change in the pond’s surrounding area’s aesthetics if you want to get a windmill pond aerator.

Furthermore, many neighborhoods might not allow them, so they are likely only suited to rural or industrial settings.


The disadvantage of windmill pond aerators is that the air pump compressor is driven by wind. Most windmill aeration systems can work with wind speeds as low as five miles per hour, but if the wind is slower than that, there will be no aeration.

Well, what can you do about it?

Depending on your pond’s size and depth, a wind and solar power mix could be the best choice. When the wind blows, a wind-powered option will provide the aeration and oxygen, and in less windy conditions, a solar-powered pump will provide the backup aeration. Both are environmentally safe and cost-effective ways to aerate your pond, and neither uses electricity.

Things to Consider When Choosing Wind-Powered Pond Aerators

These are some things to keep in mind when you’re about to purchase a windmill pond aerator.

Airflow & Aeration Potential (CFM)

Ensure the windmill you buy will give the right amount of airflow (oxygen) for the amount of water you have. If this will be your primary source of aeration and you don’t have a backup system, we still suggest getting a slightly bigger model that can deliver more CFM even in low wind conditions.

The air volume that can come from a pressurized storage container using an air compressor is measured in cubic feet per minute (CFM). Top-of-the-line wind-driven aerators would be capable of producing at least three CFM of airflow, which will be sufficient for ponds larger than an acre or with a capacity of 30,000+ US gallons.

Also, realize that you may need more than one bottom diffuser if your pond is not circular.  Bottom aeration works best in deep, circular ponds.  The deeper the pond, the more pressure it will take to push air to the bottom, so you will need to check the psi rating on your windmill.  Diffusers are more effective in deeper ponds because the air bubbles spread out wider in the water column as they raise to the surface, turning more water.

If your pond is more shallow or you have an oval or oddly shaped pond, you may want multiple diffusers to be sure that you are turning the water sufficiently.

Height of Tower & Blade Length

Windmill aerators come in many sizes, from nine-foot towers for backyards to larger than 30-foot towers for big outdoor ponds. Finding a sweet-spot for optimal aeration is critical because air currents’ intensity increases with height when there are fewer ground-level blockages.

For instance, if you’re putting a smaller tower in your garden and have a seven-foot-high enclosing wall, you’ll need a tower that’s at least seven feet tall to capture upper-level air currents. This is why windmills are very well fitted to remote sites, where height is less of an issue, and you can go even bigger to improve aeration capacity without bothering the public.

So, what’s the sweet spot for height? The head of your windmill needs to be higher than any visible barriers and as far away from structures that would possibly impede incoming winds.

Additionally, you can also consider the tower head where you’ll find the moving blades—the bigger the blades, the more energy you’ll produce. However, you’ll need significantly more wind, as a general rule.

If your blades are too big, they’ll need lots of wind to work and might even stop working entirely in light winds. Similarly, if they’re too small, they may not be able to generate enough energy to allow for proper airflow. 

While fan head sizes vary by manufacturer, for higher remote towers, we suggest a fan head size of 60-80 inches, and for backyard towers, a fan head size of 30-60 inches.

Bearing Fatigue and Reliability

Bearing fatigue is the primary weakness of wind-driven windmills and turbines. This is a problem for all existing turbines around the world!

Bearings support the turning shaft that the turbine’s blades are attached to. You can expect bearings to last around ten years until you need to replace them. And larger bearings usually last longer than small pieces. If you’re lucky (or you nailed the installation and maintenance), they can last twenty years.

But you should understand that larger bearings decrease total machinery reliability by increasing friction, whereas smaller bearings are more efficient but can fatigue faster.

Take your time to research windmill manufacturers and find one with a good track record of bearing stability and durability. Make sure the windmill is engineered against bearing fatigue, which ensures bearings have been custom sized for that model for greater durability.

As with purchasing any large piece of equipment, it is advisable to find a manufacturer with a good reputation for customer support, and that has experts who are willing to help, should you run into trouble in the future or if you have questions during installation.


FAQ About Windmill Pond Aeration

What are possible problems you can have with windmill pond aeration?

It changes the overall look of your landscape.

One of the most glaring issues that can arise after installing a windmill pond aerator is transforming your landscape’s general appearance. Windmills need complete access to the wind for peak efficiency, which implies a windmill would be the most prominent element of your landscape. A windmill would better blend in larger landscapes since there is more space for other features.

Stormy weather

Although windmills are built to harvest the wind’s energy, too much wind will destroy and ruin them. Extremely strong gusts can endanger the windmill and residents in the surrounding area, as dropping blades can be fatal. Checking the windmill pond aeration system’s wind rating will help you avoid damage from storms and strong winds.

Insufficient wind

One of the most serious issues with a windmill pond aerator is that it operates only when there is wind. Because of this, windmill aerators can only be used in locations where there is a consistent supply of wind. You can go with mechanical or electric aerators for better pond circulation if it is located in a low-wind environment.


Similar to other forms of pond aeration, the windmill pushes air through tubes that feed the diffusers. Debris and particulates present in the pond water may clog this diffuser, as well as the tubing that feeds it, over time. Cleaning is expected regularly to ensure that the air supply system is in good working order.


Animals, and other general wear and tear, can cause aeration tubes to leak in a windmill aerator. A leak reduces the pressure pushing air into the airline diffuser, which decreases the amount of oxygen incorporated into the pond. Leaks may be reduced by burying or sealing above-ground parts of aeration tubing.

What size of windmill compressor is right for my pond?

Like electrical aerators, you’ll want to ensure the optimum CFM of a windmill aerator is appropriate for the scale and volume of your pond. Blade length and tower height are critical factors to consider, but they won’t matter if your aerator doesn’t supply enough air circulation for your pond.

While there is no definite formula for measuring CFM to water volume, the list below gives a rough guide.

  • 1000-4000 US Gallons: 0.50-0.80 CFM
  • 4000-8000 US Gallons: 0.80-1.20 CFM
  • 8000-16000 US Gallons: 1.20-2.00 CFM
  • 16000-32000 US Gallons: 2.00-4.00 CFM
  • 32000 US Gallons or more: 4.00 CFM and more 

Is wind power acceptable for backyard ponds?

Wind power is ideal for huge open areas where you can catch lots of air currents without being obstructed by walls, trees, or nearby structures since they can quickly minimize winds. Installing turbines in backyards has the downside of needing additional height for maximum airflow, which can turn them into an unsightly feature in your landscape.

There are smaller-scale windmill solutions available that can provide aeration even without much height if you’re trying to push aeration for a smaller pond and don’t need huge air pressure quantities. Some of these are repurposed ornamental windmills attached to an aeration device to provide adequate airflow for backyard ponds.

That being said, a word of caution: any form of turbine aerator is far more challenging to set up than a solar-powered or electric-powered aerator. To complete the extra measures required to get the equipment together and in proper working order, you’ll need some DIY experience.

What about low wind speed conditions? Will I still have aeration?

Wind-driven pond aerators typically do not have any backup, so you have no aeration if there is no wind. 

There are ways to combine electric and windmill aeration systems so that you can have the electric aerator work if the wind stops, but this would require access to electricity.

If you have a pond that needs continuous aeration, such as a giant koi pond, a backup aerator is often recommended in case the primary one fails. A standard electrical aerator can be kept on hand to use as a manual backup device should your primary aeration fail.

A healthy pond will not deteriorate quickly if the wind stops blowing for a bit.  The real concern would be that if you are in a hot location, your pond is shallow, and you have many fish, the warm, shallow water would not hold much oxygen for the fish if the windmill stopped for a long time.

If you don’t have access to a power supply, a solar-powered device can be used as a backup to a wind-powered system – but depending on the size of your pond, this may be very costly.

But don’t worry: even in extremely low wind conditions, the top-quality windmill models will still have excellent air capture. In conditions with winds as low as seven to ten MPH, most will manage to provide aeration, albeit at a decreased rate.

Your windmill’s minimum running speeds are a significant measure of efficiency since better-optimized blades and designs can generate power even in low pressure.


Hopefully, this article has helped to inform you about windmill pond aeration. If you have a large pond that does not have electricity nearby and you live in a rural area, then windmill aeration might be perfect for you.

Pond aeration is the single best thing you can do to improve your natural bottomed pond’s water quality, so installing a windmill will definitely help. Windmill aeration is also safe and very eco-friendly, so not only are you helping your pond, but you are also helping the environment.


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