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.
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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: https://rsscience.com/microscopic-organisms-pond-water/
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:
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:
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.
Salmon:
- 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.
Bluegill:
- 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:
- 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:
Temperature:
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
Turbidity:
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.
References:
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.
