The Best Fish for Aquaponics

Aquaponics is a symbiotic system where fish and plants coexist and benefit from each other's presence. In this ecosystem, fish provide the nutrients for plant growth through their waste, while plants help purify the water, thus creating a closed-loop and highly efficient system.

However, the success of an aquaponics system depends on one crucial decision: choosing the best fish species. Fish play an essential role in maintaining the delicate balance of this self-sustaining environment. Their needs, behaviors, and compatibility with the chosen crops can significantly impact your aquaponics system's productivity and health.

In this article, we will discuss fish selection in aquaponics systems. We'll explore the key factors to consider when choosing fish for your system, discuss the advantages and considerations of popular fish species, and provide insights into their compatibility with different plants. Whether you're a beginner looking to start your aquaponics journey or an experienced enthusiast seeking to refine your system, understanding the best fish for aquaponics is essential for a thriving and sustainable system. 


catfish in aquaponics


The Importance of Choosing the Best Fish For Your Aquaponics System

Choosing the best fish to raise in your system is an essential decision, as it directly impacts the overall health and productivity of the system. Fish species have varying water temperatures, diets, growth rates, and disease resistance requirements. Selecting the wrong fish can lead to imbalances in the system, hinder plant growth, and even jeopardize the fish population. Choosing the right fish can optimize nutrient production and enhance the overall sustainability and efficiency of the aquaponic setup.

Key Considerations for Choosing Aquaponics Fish

Below are the factors to consider in choosing the best fish for your aquaponics system.

1.Water Temperature Requirements

  • Warmwater vs. Coldwater Species: One of the foremost considerations when selecting fish for your aquaponics system is their temperature requirements. Fish can broadly be categorized into warmwater and coldwater species. Warmwater fish, like tilapia, prefer water temperatures of 75 to 85°F (24 to 29°C). Coldwater fish like trout thrive in cooler temperatures, typically between 50 to 70°F (10 to 21°C). The choice between warmwater and coldwater species largely depends on the climate in your region and the level of temperature control you can maintain in your aquaponics setup.
  • Finding the Right Temperature Range for Your Region: It's crucial to choose fish that can comfortably adapt to the environmental conditions in your area. If you live in an area with extreme temperature fluctuations, consider investing in heating or cooling systems to maintain a stable water temperature.

2.Growth Rate and Harvestability

  • Fast-Growing Species: The growth rate of your aquaponics fish is a key factor in maximizing the yield of your system. Choosing fast-growing species can result in quicker harvests and a more efficient production cycle.
  • Harvesting Considerations: Before selecting a fish species, consider how you plan to harvest them. Different fish have varying harvest methods, such as netting, trapping, or spearfishing.

3.Diet and Feeding Habits

  • Herbivorous vs. Omnivorous vs. Carnivorous Fish: Fish have diverse dietary requirements. 
  1. Herbivorous fish primarily consume plant matter.
  2. Omnivorous fish have a mixed diet of both plant and animal-based foods. 
  3. Carnivorous fish predominantly eat other fish or smaller aquatic organisms. 

Consider the dietary preferences of your chosen fish species and how they align with the plants you intend to grow. 

  • Balancing the Diet in Aquaponics: It's essential to balance the type and quantity of fish and the nutritional needs of your crops. Overfeeding fish can lead to excess waste, while underfeeding can result in nutrient deficiencies for your plants. Regular monitoring and adjustment of feeding habits are critical to maintaining a balanced aquaponics system.

4.Space and Tank Size Requirements

  • Fish Tank Size Relative to Plant Bed Size: The size of your fish tank should be proportional to the size of your plant beds. Fish produce waste continuously, and it's essential to ensure that there is enough water volume to dilute and distribute these nutrients effectively to the plants.
  • Overcrowding Concerns: Overcrowding can lead to stress, disease, and poor water quality for the fish. Calculating the appropriate stocking density based on the species and the tank size is essential. Avoid overcrowding, as it can harm both fish and plants.

The Best Fish Species for Aquaponics

1. Tilapia

Nile Tilapia


Ideal pH Range: 6.5 - 9. 
Ideal Temperature Range: 82 - 86 °F
Ideal Fish Tank Size: A fully grown tilapia will weigh 1 pound, although they can grow larger. The rule of thumb is that one pound of tilapia will need 3 gallons of water. This means that in every 3 to 5 gallons of water, only raise one tilapia.
Temperature Requirements: Ensure the water temperature is suitable for tilapia, generally between 75-85°F (24-30°C).

Advantages of tilapia in aquaponics:

  1. Rapid Growth: Tilapia are known for their fast growth rate, making them an excellent choice for aquaponics. They reach harvestable size quickly so you can enjoy a consistent supply of fish.
  2. High Reproduction Rate: They reproduce readily, helping maintain a steady fish population.
  3. Wide Temperature Tolerance: Tilapia can adapt to various water temperatures, making them suitable for various climates.
  4. Hardiness: They are hardy fish that can tolerate fluctuations in water quality, making them forgiving for beginners.
  5. Mild Taste: Tilapia have a mild, white flesh that is palatable to most consumers, making them a popular choice for aquaponic growers.

Considerations of raising tilapia in aquaponics:

  1. Dietary Needs: Tilapia are primarily herbivorous but can be omnivorous to some extent.
  2. Warm Water: While they can adapt to varying temperatures, tilapia thrive in warmer waters. In cooler climates, you may need heating systems to maintain ideal conditions.
  3. Breeding: Tilapia can reproduce prolifically, which can lead to overpopulation if not managed carefully.

    We Offer Two Types of Tilapia For Sale

    Tilapia For Aquaponics

    2. Trout

    Trout Fish


    Ideal pH Range: 6.5-8
    Ideal Temperature Range:14-16°C (57-60°F)
    Growth Rate: 1000 grams in 14 to 16 months

    Advantages of trout in aquaponics:

    1. Coldwater Compatibility: Trout prefer cooler water temperatures, making them suitable for regions with colder climates.
    2. High-Quality Flesh: Trout offers a delicious meat with delicate flavor and texture.
    3. Disease Resistance: They tend to be hardy fish with good disease resistance, provided water quality is maintained

    Considerations of raising trout in aquaponics:

    1. Temperature Sensitivity: Trout are sensitive to temperature fluctuations, and water temperature should remain within their preferred range. This might require additional heating or cooling systems.
    2. Slower Growth: Compared to tilapia, trout have a slower growth rate, which means a longer time to harvest.
    3. Oxygen Requirements: Trout are oxygen-demanding fish, so you must ensure excellent aeration in your system.

    3. Catfish



      Ideal pH Range: 7 -8
      Ideal Temperature Range: 65°F to 90°F
      Ideal Fish Tank Size:Large fish tank (at least 8 gallons of water per catfish).

      Advantages of catfish in aquaponics system:

        1. High Yield: Catfish are known for their substantial yield, making them popular for commercial aquaponics systems.
        2. Adaptability: They can tolerate a range of water qualities and are less sensitive to water parameter fluctuations.
        3. Omnivorous Diet: Catfish are omnivorous and can consume various foods, allowing flexibility in their diet.

          Considerations for growing catfish in aquaponics:

            1. Water Temperature: While catfish are hardy, they do best in warm water, so maintaining suitable temperatures may be necessary.
            2. Size Management: Catfish can grow quite large, so ensure your system can accommodate their size.
            3. Handling: Catfish have sharp spines on their fins, which can cause injury if not handled carefully.

              4. Largemouth Bass

                Largemouth Bass
                Ideal pH Range:6-8
                Ideal Temperature Range:65°F - 80 °F
                Ideal Fish Tank Size:A 100 to 150 gal (380 to 570 L) tank is a great size to start with. This would be enough to house eight fish, given they’re no more than 10 inches in length.


                Advantages of largemouth bass:

                1. Bass are top feeders.
                2. Bass eat almost anything like insects, worms, and pellets.
                3. They don't need much protein, giving you more food choices when feeding them.
                4. Great-tasting fish to eat.

                Disadvantages of Largemouth Bass:

                1. The potassium levels of Bass need to be monitored as changes in this can make them ill.
                2. Their conditions must be monitored closely to ensure clean water, correct oxygen, and pH levels.
                3. Bass do not tolerate bright light and have poor feeding habits.

                5. Salmon

                  Salmon in Tank


                  Ideal pH Range: 7 - 8
                  Ideal Temperature Range: 55°F - 65°F
                  Ideal Fish Tank Size:A 1000-L tank (264 G) is enough to house four fish for Atlantic salmon. 
                  Food Requirements: Salmon can be fed with pellets that contain 70% vegetable ingredients and 30% marine ingredients like fish oil and fish meal.
                  Salmon are great-tasting and one of the best fish to raise in your aquaponics system if you live in a colder climate. They require a larger fish tank to thrive and can take about two years to reach full size.

                  Advantages of Salmon:

                    1. Delicious and healthy to eat.
                    2. Salmon are social fish, tolerant and friendly with other fish.
                    3. Salmon has a high tolerance for cold conditions.

                      Disadvantages of Salmon:

                        1. They require more food than other fish.
                        2. Salmon are more likely to contract diseases than many other fish species.

                        Ornamental Fish

                              1. Koi

                              Koi Fish
                              Ideal pH Range: 6.5 - 8
                              Ideal Temperature Range:65°F - 78 °F 
                              Ideal Fish Tank Size: A 1000-gallon tank will be enough to have 6-5 koi. They are also ideally grown on ponds.

                              Advantages of raising koi:

                                1. Disease and parasite resistance.
                                2. It can survive in a wide range of temperatures.
                                3. Ornamental and attractive fish.
                                4. Long lifespan.

                                Disadvantages of raising koi:

                                    1. Not a good fish for eating.
                                    2. Needs a larger fish tank. 
                                    3. It can produce excess waste as they age and require more cleaning to keep your system healthy.

                                      2. Goldfish

                                          Ideal pH Range:6 - 8
                                          Ideal Temperature Range: 78°F- 82 °F 
                                          Ideal Fish Tank Size:At least a 120-gallon tank for five single-tailed goldfish.

                                          Advantages of raising goldfish:

                                            1. Goldfish is a beautiful ornamental fish.
                                            2. Hardy fish and tolerant of pH changes.
                                            3. It can live in polluted water.
                                            4. Produce lots of beneficial waste nutrients for the plants.

                                              Disadvantages of raising goldfish:

                                                1. You can't mix them with other fish in one tank.
                                                2. Not edible.

                                                3. Gourami

                                                Gourami fish in aquarium

                                                Advantages of raising gourami in aquaponics:

                                                1. Ornamental Value: Gourami are often chosen for their vibrant colors and unique appearances, adding an aesthetic element to your aquaponics system.
                                                2. Peaceful Nature: They are generally peaceful and coexist well with other fish and plants.
                                                3. Adaptability: Gourami can adapt to a range of water conditions, making them suitable for different aquaponics setups.

                                                Considerations of raising gourami in aquaponics:

                                                1. Non-Edible: Gourami are primarily ornamental fish and are not typically harvested for food.
                                                2. Compatibility: Ensure that gourami is compatible with the plants you intend to grow, as they have different dietary preferences than typical aquaponics fish.
                                                3. Breeding: Some gourami species are known to breed readily, so be prepared for potential population growth in your system.

                                                  Fish Care in Aquaponics Systems

                                                  A. Feeding the Fish in Aquaponics

                                                  Here's how responsible feeding practices contribute to the overall health of your aquaponic setup:

                                                  1. Balanced Diet: Choosing the right fish food is essential. Opt for high-quality, nutritionally balanced feed that meets the dietary requirements of your specific fish species. Well-fed fish produce nutrient-rich waste that benefits your plants.
                                                  2. Feeding Frequency: Establish a consistent feeding schedule to avoid overfeeding or underfeeding. Overfeeding can lead to excess waste and water quality issues, while underfeeding can result in nutrient deficiencies for both fish and plants.
                                                  3. Monitoring Appetite: Pay attention to your fish's appetite and adjust feeding quantities accordingly. Fish may eat less during colder seasons when their metabolic rates decrease, and plants require fewer nutrients.
                                                  4. Avoid Overfeeding: Overfeeding can lead to excess nutrients in the water, causing imbalances and potentially harming fish and plants. Uneaten food should be promptly removed from the system to prevent decomposition and water contamination.

                                                  B. Acclimating Fish in Aquaponics

                                                  In adding fish to the system, it is essential to acclimatize the fish first, to remove the stressful factors that can cause death to the new fish. The two simple ways of acclimating your fish are:

                                                  1. Keep the new fish in a small aerated container with their original water and slowly add water from the fish tank over a day. 
                                                  2. Slowly allowing the temperature to equilibrate by floating the sealed transportation bags containing the fish in the fish tank for at least 15 minutes. Then slowly add a small amount of fish tank water to the transportation bag. 

                                                  C. Observing Fish Health and Behavior

                                                  The primary indicator of fish health in your aquaponics system is their behavior. It is essential to recognize the behavior of your fish and look for signs of fish stress, disease, and parasites to maintain healthy fish.

                                                  Here are some important ways of maintaining healthy fish in your aquaponics system:

                                                  1. Observe fish before and after their daily feeding and note how much feed is eaten.
                                                  2. Observe and take notes of the fish's behavior and appearance daily.
                                                  3. Understand the signs of fish stress, disease, and parasites.
                                                  4. Maintain a low-stress environment with consistent good water quality, specific for the fish in the system.
                                                  5. Maintain the correct water temperature suited for the fish in the tank. 
                                                  6. Use the proper stocking density and feeding rates.

                                                  Healthy Fish Behavior:

                                                  Healthy fish in your system shows the following behavior:

                                                  1. Extended fins and straight tails.
                                                  2. A graceful pattern of swimming. No lethargy. However, catfish often sleep at the bottom of the fish tank until they wake up and begin feeding.
                                                  3. A healthy appetite and not shying away at the presence of the feeder.
                                                  4. No marks, discolored blotches, streaks, or lines.
                                                  5. Not rubbing or scraping on the sides of the fish tank.
                                                  6. Sharp, clear, and shiny eyes.

                                                  D. Fish Diseases in Aquaponics

                                                  Several conditions can cause fish health problems in your aquaponics system: fish disease, parasites, fungus, and bacteria. These can all appear in your fish tank and quickly spread disastrous effects on the fish. The chance of fish disease or stress is incredibly high when you introduce new fish or add fresh water to your system, as the new fish might have brought diseases with them.

                                                  Prevention is the best way to prevent disease in fish, and recognizing the signs of fish diseases can help you avoid the loss of fish in your aquaponics system. In preventing fish disease, it is essential to check your fish regularly for any of the following signs:

                                                  • Check their appearance regularly because several parasitic and fungal infections can be visible on the fish skin, scales, or fins.

                                                  Most external signs of fish disease are:

                                                  1. Ulcers on the body surface, discolored patches, and white or black spots.
                                                  2. Fin rot, ragged fins, or exposed fin rays.
                                                  3. Abnormal body configuration, twisted spine, and deformed claws.
                                                  4. Swollen appearance and cotton-like lesions on the body.
                                                  5. Exophthalmia or swollen popped eyes.

                                                  • Check for behavior changes, such as your fish becoming lethargic, refusing to eat or changing feeding habits, changing swimming patterns, odd position in water, head or tail down, difficulty maintaining buoyancy, and fish gasping at the surface.
                                                  • If your fish looks bloated or their scales seem raised, it also indicates health concerns.

                                                  Causes of Fish Diseases

                                                  Fish diseases can be introduced by adding new fish, poor water quality, live food, invertebrates, or equipment used in the system. Like other animals, fish also carry bacteria, viruses, fungus, and parasites. Though not all these bacteria are harmful, some of these microorganisms, called pathogens, can potentially cause fish diseases. 

                                                  The following factors can cause fish disease in your aquaponics system.

                                                  • Adding new fish to the system
                                                  • Environment or poor water quality
                                                  • Fish stress
                                                  • A poor or unbalanced diet
                                                  • The equipment used in the system is not suitable for the fish
                                                  • Not getting along with other fish species in the fish tank

                                                  Symptoms of diseases to look out for:

                                                  • Cloudy or swollen eyes.
                                                  • Rapid movement of the gills.
                                                  • Distended or hollow stomach.
                                                  • Opaque, clamped, or frayed fins.
                                                  • Wounds, fungus growth, patches or spots of cloudy white/grey, or color changes in the skin. 
                                                  • Unusual behavior. (unusual swimming patterns, darting around the tank in an alarmed fashion, hanging at the surface or hiding away and being unusually shy).

                                                  How to Prevent Fish Diseases

                                                  • Purchase healthy fish seeds from a reputable and reliable hatchery.
                                                  • Never add unhealthy fish to the system. Examine and quarantine new fish in a separate tank for two weeks before introducing them into an established fish tank. 
                                                  • Feed the fish with a good, varied, and well-balanced diet.
                                                  • Keep the water quality in your system clean, including cleaning the filter if you have one fitted to your system.
                                                  • Ensure the system is within the parameters of pH, ammonia, nitrites, and nitrates for your particular fish.
                                                  • Add extra aeration. You can rarely have too much aeration.
                                                  • Reduce the frequency of opening and closing the lid on the tank and minimize scooping fish out to inspect them. 
                                                  • Treat the disease as soon as it is identified.


                                                  Aquaponics is a sustainable and efficient farming method that harnesses the symbiotic relationship between fish and plants. Whether you choose common species like tilapia and trout or explore lesser-known options like barramundi careful consideration of water quality, feeding strategies, and fish health is essential.

                                                  The fish species mentioned above are the best fish for aquaponics systems. However, choosing the best aquaponic fish species in aquaponics is not enough; managing your system correctly is also essential. A proper management practice will help keep your fish happy and healthy. Hopefully, this article enables you to make choosing the best fish for your system quicker and more enjoyable!

                                                  3 Responses

                                                  Jazmine Montoya

                                                  Jazmine Montoya

                                                  February 08, 2022

                                                  What kind of High protein food would I give my catfish ?



                                                  August 05, 2020

                                                  Wondering about light/dark … for example, if I went with bass in a large tank set into the ground… do the fish want or require an amount of daylight or can they thrive in mostly dark? (very much still in design phase)

                                                  Thanks for any insight on this as I’m not seeing it mentioned anywhere.



                                                  March 04, 2020

                                                  As for me I like the male [SMALLMOUTH BASS] as pets only and I would get a long long long long long wide 40 gallon tank with a tall thick brush of bluepurple tricolor plants I will add 3 pumpkinseed sunfish, 3 semi-aggressive geophagus cichlids and 1 single big male Rio grande texas cichlid.

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