How to Choose the Right Fish Tank for Aquaponics - Go Green Aquaponics

How to Choose the Right Fish Tank for Aquaponics

In setting up your own aquaponics system, you can purchase a fish tank or design a do-it-yourself fish tank at home. A fish tank is one of the main components of an aquaponics system and plays an essential role as they provide a place for the fish to live. So whether you decide to purchase or make your own aquaponics fish tank, it is essential that you choose the right one to ensure your money and hard work are not wasted.

In choosing a fish tank for your aquaponics system, there are several considerations that you need to make to ensure that your fish tank can provide a conducive environment for fish. 

Aquaponics Fish Tank

How to Choose the Right Fish Tank for Aquaponics?

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

Fish Tank to Grow Bed Ratio

The recommended fish tank to grow bed ratio in aquaponics is approximately 1:1. Meaning the fish tank volume should be equal to the grow bed's volume or 6 gallons (22 liters) of fish tank to every cubic foot of grow bed. You can extend the ratio to 2:1 but be sure to reduce your fish's stocking density as this ratio can reduce your ability to filter the fish tank water with the plants in the grow bed.

Take note that this is just the recommended ratio. As an aquaponics grower, you can make your own ratio because it all depends on your system, geographic location, and the type of fish you choose. 

Things to Consider in Choosing an Aquaponics Fish Tank Size

The type of fish you want to raise and the size of the aquaponics system you want to build will determine the fish tank's size. Indoor aquaponics systems that grow aquarium fish as pets or decorations use aquariums that are often made of glass or transparent plastics.

For aquaponics growers who want to grow edible fish, you need a larger tank to have stability in your aquaponics fish tank. A small 20 to 30-liter fish tank is only limited to growing small aquarium fish like guppies and other small fish. At the same time, a 200-gallon fish tank that is 2 feet deep can grow 50 up to 100 tilapia fish. It would help if you calculated the right fish tank to plants ratio to have a balanced system.

Tank Shape

Any shape of a fish tank will work, but the two most common shapes of fish tanks used in aquaponics are the round/oval tank and square/rectangular tank. Round tanks with a flat bottom are the most preferred because they are more effective than the rectangular shape fish tanks.

Benefits of Using a Round or Oval Fish Tank:

  1.  A round tank will allow the water to circulate evenly and transport solid wastes into the tank's center by centripetal force. 
  2. A circular-shaped fish tank provides excellent water flow that provides fish with a current to swim against, which increases fish health. 
  3. 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. 
  4. A round fish tank increases the fish's oxygen benefits and the nitrifying bacteria in your system and inhibits harmful bacteria that thrive in an anaerobic environment.
  5. Fish can circulate easily in a round fish tank.
  6. Solid wastes are suspended in the water and will not stick to the corners of the fish tank.

Square shaped tanks are acceptable, but they require regular solid waste removal. 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 (Intermediate Bulk Container), or high-quality food-safe bulk shipping containers, are widely used square fish tanks.

Tanks with non-geometric shapes with curves and bends can create dead spots in the water with no circulation. These areas can gather wastes that can create dangerous conditions for the fish. You can still use an odd-shaped tank, but you must add a water pump to ensure that there is proper circulation, and you must also remove the solids regularly.

Aquaponics Fish Tank


Inert plastic or fiberglass is recommended because of its durability and long life span. Plastic and fiberglass are also light, easy to move, easy to install plumbing, and cheap. Do not use metal for your fish tank because it is prone to rust. 

Requirement for choosing your fish tank:

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. 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 environment's temperature.

3. Toxic-Free- It is important that your fish tank does not comprise toxic material that could harm your fish or 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 contain any toxic substances before.

You can also use second-hand containers such as barrels, old bathtubs, or intermediate bulk containers (IBC) as fish tanks. Just make sure that the container was not used to store toxic materials or chemicals.


As much as possible, use white or light-colored fish tanks because they allow for easier viewing of the fish. White tanks will also reflect sunlight and keep the water cool. 

Cover and Shading

Fish really do not need much light, they want to feel safe and secure. That is why it is essential to have a cover on your fish tanks. The covers will also prevent fish from jumping out of the tank and prevent leaves or other materials from entering. The cover will also prevent predators such as cats and birds from attacking the fish. A fishing net will make a great cover, while agricultural shading nets work well in shading your fish tank. Shading your fish tank will prevent algal growth.

Fish in Aquaponics Fish Tank


Lastly, one of the important questions you need to ask yourself in determining what type of fish tank you want to use in your system is;Are you planning to raise edible fish, or do you want a decorative fish? After you have answered this question, you will know the right fish tank for your aquaponics system.

Choosing the right fish tank might be overwhelming, but you must choose the right one for your system to ensure its success. Once you have the right fish tank, it is essential that you will not overcrowd the tanks. Your aquaponics system will be easier to manage and insulated against shocks and collapse if you keep the stocking density low. Thank you for reading this article. Our article, The Ultimate Aquaponics Beginner’s Guide, will guide you in setting up your own aquaponics system.

1 Response



July 27, 2021

Dear Sir.
Thanks for this excellent and easy to understand article; with a lot of technical information that are professionally simplified to be helpful for anyone with little or no previous knowledge about aquaponics.

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