Can You Eat the Fish from Aquaponics?

Aquaponics fish have high nutritious value and are good for your health. This is because the environment where these fish grow contain less chemicals. In the aquaponics fish tank, the fish enjoy fresh and clean water supply that the plants in this system purify.

However, the kind of fish you can eat from this clever farming technique depends on why you opt for this system. It will be an aesthetic system if you rear koi or red ear sunfish as you’re not supposed to eat the ornamental fish. Tilapia or catfish are edible and are some of the best species for harvesting.

So, if you’re planning to start an aquaponics fish farm and wondering whether it’s okay to eat them, this article is for you.

Is It Healthy to Eat Fish from an Aquaponics System?

Yes. If you rear edible aquaponics fish, you’re free to eat them at maturity. This kind of fish has an immense nutritional value which is good for your health. 

Remember, the aquaponics fish tank contains purified, chemical-free water safe for the fish. You’ll not have any complications when you eat them as they’ve no harmful chemicals in their bodies.

The aquaponics fish also grow in the best environment, ensuring they’re stress-free and healthy. So, if you eat them, you’ll be healthier as the omega-3 fatty acids from the fish and vitamins will boost your body.

Aquaponics Catfish

Types Of Aquaponics Fish You Can Eat

Before you invest in aquaponics, you first need to understand the best fish for aquaponics and identify the purpose of starting the system. Note that some people use the aquaponics system for decorative purposes, while to others, it’s a source of income/food as they harvest them. So, if you want to harvest your aquaponics fish at maturity, here are the best species to go for:


Catfish is one of the best fish for aquaponics that’s easy to grow and feed. It can withstand any water condition and adapt fast to the environment. It will take about 5 to 10 months for this aquaponics fish to mature.


You will not regret introducing tilapia into your aquaponics fish tank as it’s easy to take care of and adapts to the environment faster. The edible fish is delicious and is most people’s choice as it’s easy to cook.

Tilapia is also a good protein source and takes less time to mature and reproduce at a high rate. If you want to harvest it for food, you’ll have plenty after some time.


Eating trout from your aquaponics system will also be beneficial to your health. It has high protein and fatty acid levels, good for the human body. You can have it in your tank during winter as it’s a cold-water fish.

If you opt for trout, your aquaponics fish tank needs to be bigger, and you’ve got to maintain high hygienic standards.


You will also love eating perch from your aquaponics system after about 9 or 16 months of hard work. This fish is very nutritious as it feeds on other small fish. The perch fish are a good choice for beginners as they adapt faster to the environment giving you less stress when caring for them.

How Many Fish Can You Have in An Aquaponics System?

You need to know the number of fish your aquaponics system can hold beforehand for budgeting. Since the fish will stay here up to maturity, it’s also best to know their numbers to provide adequate space to make them comfortable and not contribute to any stress. 

The number of fish depends on the size of the tank you’ve got. A bigger tank will allow you to have more fish, while a smaller one will restrict the numbers.

The aquaponics fish also require enough water volume to survive and have a balance between the plants and fish. For example, if you’ve many edible fish, they’ll not be comfortable contributing to stress. 

On the other hand, few fish will create an imbalance in the system as the bacteria will have less fish waste to convert to nitrates. This means the bacteria will take longer to produce sufficient nitrates that your plants can feed on, making them unhealthy.

So how many fish are ideal for an aquaponics system? Continue reading to know the factors determining the number of fish for your aquaponic system.

Aquaponics Fish

The Tanks Shape

The number of aquaponics fish will depend on the shape of the tank you’ve got. A rectangular tank will have a different water volume from a circular one. 

The tank’s shape also determines the surface area available for the fish’s survival as it creates room for oxygen and carbon exchange in the water and air. A deeper tank with enough surface area also enables fish to hide from predators.

The bigger the surface area per gallon of water, the less fish can survive as food will not be evenly distributed.

It’s advisable to go for the round bottom tank to offer better water circulation and light distribution. It is also good for waste removal, keeping your fish healthier, and allowing more fish into the system.

Quality Of Water

The quality of water you’ve got in your aquaponics system also affects the number of aquaponics fish to stock. If you’re using high-quality water, you can have more fish in the tank as the Ph and temperature levels are favorable.

But if the water is low quality containing chemicals, you’ll have a lot of work to do while taking care of your fish. So, the more the number of fish, the more work (checking the tank and water Ph level).

The Kind of Fish You Opt For

Another thing that determines the number of aquaponics fish in your system is their species. If you opt for fish that require intensive care, it is best to have them in smaller numbers. So, go for species that require less care to enable you to have more fish in the tank. An example is a tilapia which can survive in different Ph and temperature levels.

Water Temperature

You will be in control of the water temperature of your aquaponics system. This means if you’re able to maintain the temperature at habitable levels, you can have more fish without any getting affected.

Stock less fish to reduce losses if you’re in an area with extreme temperature and can’t control the temperature,

How Do I Keep My Aquaponic Tank Clean?

After allowing your aquaponics fish in the fish tank for some time, you need to clean it. Cleaning the tank will help do away with dirt like bacteria and fish wastes that can cause blockage on the pump.

It will also ensure that the fish get a fresh water supply that’s good for their health. However, the cleaning method varies with the aquaponic system’s size and the stocking density. 

Here are the tips on how to clean the tank;

  • You can do that using a fine mesh scoop net which will remove the dirt at the bottom of the tank. You’ll do this with ease if you’ve many fish that stir the bottom of the tank keeping the dirt in suspension. This will push them to the pump, and the grow bed, where they’ll add value to your plants.
  • If your aquaponics system is bigger, you can consider using an airlift pump to clean the tank. You can find it online or improvise it using an air pump and poly pipe.
  • But if the dirt on your tank is smooth and smaller, a large diameter hose will help you siphon out that without struggle.
  • Also, check out for algae that can affect your fish and remove them. Algae reduces the oxygen concentration in the water affecting your fish. But this can only be a menace if you didn’t shade the tank.
  • Replace the water in the tank to improve the water quality for your aquaponics fish. Drain about 1/3 of the water in the tank and refill it with a temperate dechlorinated one. Replacing the water will help remove solids that cause high heterotrophic bacteria levels that affect the nitrifying bacteria as they fight for space and oxygen. This will lead to denitrification hence no nitrogen for the plants.
  • Additionally, you need to clean the pumps to de-clog them and have better water flow. A rifle barrel cleaner can do this. While doing this, don’t forget to check the conditions of the pipes and replace old ones.
  • Lastly, do clean the air stones in the tank. Put the air stones in a bucket of water, add hydrogen peroxide then scrub to remove bioslime.

Our Verdict

Eating the right aquaponics fish will benefit you health-wise as they contain high protein levels and are also nutritious. However, to have your fish live in the aquaponics tank to harvest time, you need to maintain high hygienic standards and clean it after some time. A clean tank will make the fish happier without stress, making you harvest more.

Remember to know the number of fish in your aquaponics system to prepare for the work ahead and budget better. This number will also tell you the water volume and tank size to use for your aquaponics fish.

Aquaponic Fish Tank
aquaponics experts

Welcome to The Aquaponics Guide

Hello! We are the Johnsons and the faces of The Aquaponics Guide. We have been avid gardeners for many years and growing our own food is one of our key priorities. We have found sustainable Aquaponics farming to be a life changer, which is the reason we have created The Aquaponics Guide. 

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