Best Fish for Aquaponics

 Best Fish for Aquaponics

The fish that you decide to choose for your aquaponics system should have similar needs as far as temperature and pH to the plants that you will be growing. There will always be some compromise to the needs of the fish and plants but, the closer that they match, the more success you will have. You also need to take into consideration whether you’re raising the fish to be eaten, or simply just to correlate with your plants.

Fish play a key role in an aquaponic system, as they will be the source of natural fertilizer for the plants being cultivated. We are going to be looking at the following 7 species of fish that can be used for either of those purposes mentioned above.

SpeciesRecommended for Eating
Largemouth BassYes

What to Consider

As I have already mentioned, you need to consider whether you are raising the fish to eat or not. The inedible species such as Koi and Goldfish do have their own benefits. Goldfish, are slightly more difficult to maintain than Koi, but are much less expensive and they can be used for smaller aquaponics systems or trial runs.

Koi fish are great for beginner systems as they’re quite resilient to the volatility that a new aquaponics system can present. They’re also very resistant to diseases and parasites which are two things that can turn a well-maintained aquaponic system upside-down. Edible fishes have the obvious benefit and the larger, faster-growing fish come with their own special conditions and requirements.

The next thing that needs to be taken into consideration is breeding. Some species of fish just don’t reproduce so easily in a controlled tank. Others, such as Tilapia and Catfish breed quite quickly, which can also lead to complications if the system isn’t built properly for it.

The growth rates of fish vary by species. With your aquaponic system, it is better to have fish with a range of growth rates to harvest fish regularly over a long period of time. It is also important to consider the time of year at which the fish are ready to be harvested. Overcrowding is an issue that needs to be dealt with as an overcrowded fish tank can disrupt the oxygen and ammonia levels in the water, as can an underpopulated tank.

You will need to make sure that you maintain your aquaponic system by testing the water, changing the water and checking your equipment, but along with that, your fish will also need some maintenance. Some fish are more difficult to care for than others. Your fish may fall ill or experience bullying, resulting in you having to administer medication to your fish or put your fish into isolation.

Fish are cold-blooded animals which means that they take on the temperature of the water in which they live in, so temperature plays a very important role. It will depend entirely on the natural climate of the fish that you choose as to the temperature of the water. For example, fish originating in the lake waters of Africa such as tilapia have evolved to thrive in warm water (above 70oF), whereas fish originating in streams of North America such as trout have evolved to thrive in cold water (55oF and below).

Finally, you need to think about the pH levels of your aquaponics system. Get it wrong and it can cause poor fish growth and may even lead to the death of your fish. So, you need to know what result in high pH or low pH levels in your aquaponic system, and how you can balance the levels within the appropriate range.

It is important to match the pH of water in the fish that with that in the fish bag when you are introducing new fish into your system. The difference between the pH values should not be greater than 0.2. As with temperature, the fish and plants you select for your aquaponic system should have similar needs in terms of PH Sensitivity.


Tilapia are considered to be one of the oldest farmed fish on the planet and originated in the wild in Africa and in the Nile River Basin of Lower Egypt. These are a very popular choice of fish for aquaponics especially for beginners. Their high protein content, large size, rapid growth and palatability have made them favorable. Tilapia are also one of the easiest and most profitable fish to far due to their omnivorous diet, tolerance of high stocking densities and rapid growth. They prefer water with a pH level between 7-8.

These are durable fish that are resistant to parasites and diseases and they can also tolerate a wider range of water quality and temperature changes. They thrive in water temperatures of around 70-80 degrees F and are usually kept at around 73 degrees to accommodate the plants. They’re easy to breed and grow quite quickly – up to 2.5 lbs. in 7 months.

If choosing Tilapia, you may need to purchase a second tank as they can breed almost too efficiently – spawning every 4-6 weeks. These do however, require warm water which can get quite costly due to you needing an energy source to maintain tropical temperatures.

  • They are edible
  • They are omnivorous
  • Temps need to be between 70-80 degrees F
  • pH levels need to be 7-8
  • They breed every 4-6 weeks
  • Require an energy source
  • Great starter fish for beginners


Trout are closely related to salmon and char and are one of the most widely farmed fish in the world due to them being pretty easy to culture. Most trout live in freshwater lakes and rivers, while others live out their lives in fresh water or spend two or three years at sea before returning to fresh water to spawn. They generally feed on other fish, and soft bodied aquatic invertebrates such as flies and dragonflies. They may also feed on shrimp and small animal parts. Unlike tilapia, these will not handle dirty water.

They are somewhat bony, but the flesh is generally considered to be tasty. The flavor of the flesh is heavily influenced by the diet of the fish. There are generally three popular choices of trout for an aquaponics system – brown, rainbow, and brook. Rainbow trout are the hardiest of the three.

They are considered a cold water fish and thrive in temperatures between 55 and 65 degrees F. They require a pH range between 6.7 and 7.7.

Trout can grow to about 15 inches in 9 months but require a large lank for them to grow in. Also, they require an oxygen saturation of at least 5.5mg/L. Stocking density is something to pay close attention to so as to make sure that there’s adequate oxygen for all the fish.

  • They are edible
  • They are carnivorous
  • Temps need to be 55 to 65 degrees F
  • pH levels need to be 6.7 to 7.7
  • They require a large tank for optimum growth
  • They require an oxygen level of at least 5.5mg/L


Goldfish are a good choice of fish for an aquaponics system as they produce and eat a large amount of excretion, thus providing plenty of nitrates for the plants. They are also a fairly hardy species in most cases but this will depend on the specific species that you select. However, rapid changes in temperature can be fatal.

There are generally two types of goldfish – twin-tailed and single-tailed. Be mindful to avoid mixing these two species together as twin-tailed fish could end up suffering greatly. As single-tailed gold fish have slim bodies, and are more aggressive and faster swimmers, twin-tailed gold find it hard to compete with them.

Goldfish are inedible and more for those that are just wanting ornamental fish and they thrive in temperatures of 65 to 78 degrees F and pH levels of 6.5 to 8.0.

  • They are inedible
  • They are omnivorous
  • Temps need to be 65 to 78 degrees F
  • pH levels need to be 6.5 to 8.0


Carp are a species of oily freshwater fish that are native to Asia. There are various species of carp that can be reared as food. They are omnivorous and can feed on algae, plants, insects and many other soft bodied aquatic invertebrates. They can also easily adapt to various environments and have good reproductive capabilities.

Carp make a good species for aquaponics due to their resilience to changes in water conditions. They have a temperature range of 80 to 82 degrees F and a pH range of 7.5 to 8.0.

  • They are edible
  • They are omnivorous
  • Temps need to be 80 to 82 degrees F
  • pH level needs to be 7.5 to 8.0
  • They are resilient in different water conditions


Catfish are one of the most farmed types of fish and are sought after for their taste – their meat is consumed as a delicacy around the world. They are omnivorous bottom feeders and valuable scavengers. They can also withstand a wide range of water conditions due to them being such a strong fish. They are not territorial and can tolerate a higher stocking density. Catfish are easy to breed and grow, and within 3 months can be harvested for cooking.

They thrive in a similar temperature range as tilapia do at 75 to 85 degrees F and have a pH range of 7 to 8. They grow fast and can reach 2-3 lbs. in 12 months.

  • They are edible
  • They are omnivorous
  • Temps need to be 75 to 85 degrees F
  • pH levels need to be 7 to 8
  • They can tolerate a wide range of water conditions
  • They are a good choice for beginners


Koi are a very popular choice of fish for aquaponics enthusiasts. They have a long lifespan and can easily live and breed within the aquaponic system. They are also fairly disease and parasite resistant. They are omnivores and can eat just about any food. As they eat algae, debris and plant matter that fall into their pond, additional feeding may not be necessary but this will depend entirely on how many you have.

These are not a good choice for those wishing to raise the fish for eating. They thrive in temperatures of 65 to 78 degrees F and pH levels of 6.5 to 8.0.

They are highly successful among beginners due to their adaptability and resilience.

  • They are non-edible
  • They are omnivorous
  • Temps need to be 65 to 78 degrees F
  • pH levels need to be 6.5 to 8.0
  • They are a great choice for beginners
  • They are a hardy species
  • Resistant to most disease and parasites

Largemouth Bass

Bass are very hardy and can tolerate low water temperatures. They eat worms, insects, larvae as well as high protein pellets. They prefer to feed on food that stays in the surface or that sinks slowly, rather than to feed off the bottom of the tank.

Although we are listing Largemouth Bass here, you have many species of Bass that you can choose from. Some of the more popular species for aquaponics are the Largemouth, the Hybrid striped bass, the Smallmouth, and the Australian bass.

Though not considered a beginner species for aquaponics by any means, Largemouth bass are widely used in aquaponics systems due to their potential for growth. A full sized adult largemouth bass can reach 12 lbs. in weight in 16 months.

They do not like bright light and require a strict feeding regime of small shrimp and insects as a baby and then snails and crayfish as an adult. They require a steady water temperature between 65 to 75 degrees and prefer a pH level of 6.5 to 8.5.

Though much maintenance is required for largemouth bass, their size and hearty meat provide a very rewarding harvest.

  • They are edible
  • They are carnivorous
  • Temps need to be 65 to 75 degrees F
  • pH levels need to be 6.5 to 8.5
  • They can grow up to 12 lbs.
  • They Require a large tank for optimum growth
  • They need to be kept away from bright light


You need to take the time to choose the right fish in order to have a successful aquaponics system. It is also essential that you establish a maintenance routine, especially if you have an outdoor setup. Make sure to regularly test the water for pH, ammonia level, and temperature. Regular testing will help you notice variations that could be problematic before they harm your fish or plants.

Well that’s it for now so we hope that you enjoyed reading our guide on the best fish for aquaponics. If you’ve found this article to be useful and are interested in learning more, be sure to sign up for our newsletter.

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