How to Choose the Right Fish Tank in Aquaponics

How to Choose the Right Fish Tank in Aquaponics

Fish tanks are one of the essential components in aquaponics that you are likely to consider when you start your aquaponics system. Fish tanks are where your fish live, so it is important to choose the right fish tank carefully with an emphasis on strength, safety, water quality, and durability.

How do you choose the right fish tank for your aquaponic system?

In choosing the right fish tank for your aquaponic system, it is important to consider your grow bed. Fish tank and grow bed go together; the size of one depends on the other and vice versa. The water volume of your aquaponic system will depend on the capacity of your fish tank and grow bed.

Before choosing and purchasing your fish tank, it is important to know the ratio of your aquaponic system and make sure that your system can balance itself out.  Balance means that the amount of fish waste is sufficient for growing plants in your system. The amount of fish waste should be enough for the plants to handle. Plants help keep the fish tank clean, and if there is too much waste, the fish tank suffers, and so will your fish and plants. 

So what is your fish tank ratio to your grow bed?


The ratio to the size of your fish tank to your grow bed and plants should start as 1:1, your grow bed has to at least equal to the fish tank, not smaller. The grow bed can be larger but never smaller. Over time, you can change your ratio to two grow beds and one fish tank if you wish to expand your grow bed to have more plant options. (1)

Fish Tank in Aquaponics

Things to consider in choosing an Aquaponics Fish Tank

1. Fish Tank Materials

  1. Waterproof – The fish tank should be waterproof. If you’re opting for a used tank, check the leaks by filling up the tank with water, and use marine-grade silicone or rubber to seal if there are leaks. (2)
  2. Sturdy – Your fish tank must be strong enough to withstand the total weight of the water. It must also withstand the fish movement, and the constant stress of water as it contracts and expands, depending on the temperature of the environment. (2)
  3. Toxic-Free – It is important that your fish tank does not comprise toxic material that could harm your fish or your plants. Your fish tank should be manufactured with food-grade materials. If you use a used tank for your fish tank, make sure it is clean of toxic substances and that it did not used to contain and toxic substances before. (2)

2. Fish Tank Shape

The two common types of fish tank used in aquaponics are square/rectangular or round/oval, but round/oval is the most preferred because it is more effective than a rectangular-shaped fish tank.  

Benefits of Using a Round Fish Tank:

  • A circular shaped fish tank provides excellent water flow that provides fish with a current to swim against, which increases fish health. 
  • The fish will also enjoy playing in the currents of the water. 
  • The round fish tank provides good water circulation, and helps prevent thermal layering, and helps improve water quality. 
  • Good water movement in the fish tank increases the surface area of the tank. The constant change in the surface water increases the rate of oxygen exchange. (3)
  • Round fish tank increases the oxygen benefits for the fish and the nitrifying bacteria in your system and inhibits harmful bacteria that thrive in an anaerobic environment. (3)
  • Fish can circulate easily in a round fish tank.
  • Solid wastes are suspended in the water and will not stick to the corners of the fish tank.

Square or rectangular fish tanks are common and useful in confined spaces, both indoor or outdoor. Rectangular fish tanks are commonly found in aquarium outlets but can also be built. IBC (International Bulk Carrier) totes, or high-quality food-safe bulk shipping containers, are widely used square fish tanks. (3)

3. Fish Tank Size

The types and the sizes of fish you want to raise in your aquaponic system will determine the size of your fish tank. In an indoor aquaponics aquarium, the fish is small and limited to aquarium fish like a goldfish. So these aquariums are small and are often made of glass. But if you’re looking for a larger aquaponic system where you can grow edible fish, you need to have stability in your fish tank. So you can try to get a 150-gallon or bigger tank. A bigger tank can keep less fluctuation in temperature and pH levels.

Choosing your fish may also help in determining what type of fish tank you want in your aquaponics system.  The questions that you need to answer before buying your fish tank are: 

  1. Are you planning on eating your fish or do you want a decorative fish,
  2. What is the climate of your location?

After you answer these questions, you will know what fish to raise and what fish tank to use in your aquaponic system. Read this guide in choosing the best fish for aquaponics to help you choose the right fish for your aquaponics system. (1)

These things are important in choosing the right fish tank for your aquaponics system. There are lots of choices that can be overwhelming at first, but providing your fish with a tank that meets their needs will ensure a happy fish who will provide food to your plants. Get an aquaponics fish tank that is suitable for the size of your grow bed, your fish, bacteria, and plants, and you will have a balanced system.