Catfish are one of the most popular fish for aquaponics systems. They can tolerate a large variation in water temperatures, are not territorial, and breed ‌quickly. Catfish have a pleasant taste and are also slow-growing, so they will not outgrow your system, making them very suitable for aquaponics.

However, there are over 3,000 catfish species, and without proper research, raising catfish in aquaponics systems can be a challenge. This article discusses the essential factors you need to know about raising catfish in your aquaponics system. 

Why Raise Catfish in Aquaponics Systems?

If you are a beginner to aquaponics or looking for another fish species to include in your aquaponics system, catfish is one of the best options. Catfish are often farmed because they adapt well to fish tanks and know how to survive in different conditions. Which is an essential factor because it is not always easy to balance an aquaponics system. Aside from being adaptable to different environmental conditions, here are some benefits of using catfish in your system:

• Catfish are one of the hardy fish to raise in aquaponics.
• They are not territorial, so they can live with other fish in the tank.
• Catfish have a mild taste, making it a perfect addition to any dish. 
• Catfish can convert their food to body mass in a short period.
• They breed easily.
• Aside from commercial food pellets, they can also feed on bugs, worms, plants, and small fish.
• Catfish can tolerate higher dissolved oxygen, temperature, and pH levels.
• Catfish are disease resistant. 

The Best Catfish Varieties for Aquaponics Systems

Most catfish species thrive in an aquaponics system because they can quickly adapt to different environmental conditions. However, the three specific species listed below are the best varieties for aquaponics systems. These catfish varieties grow well in aquaponics systems and provide optimum nutrients to plants if their growing requirements are met.

Channel Catfish

Growth rate: 1 pound within six months
Feeding time:Once a day
Water temperature:75-85°F (24-29°)
pH range:7-8.5

Channel catfish is the most common variety of catfish used in aquaponics systems. This variety produces tender and good-tasting meat. The color of channel catfish will depend on the water it lives in. The channel catfish will have a dark or almost black color if the water is clear. If the water is murky, the catfish will have a yellow color. 

Eel Tailed Catfish

Growth rate: 1 pound within 18 months
Feeding time:Once a day
Water temperature:59-79°F (15-26°C)
pH range:6.5-7.5

Eel tailed catfish are another excellent catfish variety for aquaponics. This variety is omnivorous and bottom feeders. They can be fed with sinking fish pellets and alternative fish food like worms and leftover vegetables. The color of eel tailed catfish is mottled black and gray, which can change into brownish red, olive green, or brownish purple when they mature. 

Brown Bullhead Catfish

Growth rate: 1.1 pounds within two years
Feeding time: Once or twice a day
Water temperature:65-75°F (18-24°C)
pH range: 5-7

Compared to the other two varieties of catfish mentioned above, the brown bullhead catfish mature more slowly but are still hardy and grow well in the aquaponics system. This catfish variety has an olive/brown color that fades to cream on its belly. The brown bullhead catfish will have a muddy taste when grown in unclean water. 

The channel and eel tailed catfish grow faster at high temperatures and can be stocked in high densities. The brown bullhead catfish’s growth rate is not as fast as the other two. 

Growing Requirements for Catfish in Aquaponics

Water Temperature

The ideal water temperature for aquaponics catfish is between 65°F and 75°F (18°C - 23°C). Catfish are hardy fish species and can survive in varying climate conditions, but their metabolism and food consumption will decrease in cold temperatures. So for their optimum growth, it is best to keep their temperature within their ideal range.

pH

The ideal pH range for catfish in aquaponics systems is between 5 and 7.

Oxygen Requirements

Catfish need dissolved oxygen concentration of at least five mg/L and above.

Light Requirements

Catfish need sunlight to warm the water in the tank. However, they also like to hide, so provide some shade for your fish tank to keep your catfish happy.

Stocking Density

One pound of fish for eight gallons of water is the recommended stocking density for catfish.

Tank Size

Catfish can grow up to three pounds, so you will need a larger fish tank depending on how many catfish you want to raise.

Dietary Requirements

Catfish require high-protein foods. Commercial pellets fish food for catfish are available, but you can also feed them with worms, smaller fish, and left-over vegetables.

Feeding Frequency 

Feed your catfish three times a day as much as they can eat in five minutes and remove any leftover food after five minutes. 

Suitable Fish Species for Mixed Breeding in the Tank

Catfish have been known to coexist with tilapia, koi, and crappie.

How to Introduce Catfish Into Your System

You can purchase catfish fingerlings from your local pet shop or farm supplier. Some online aquaponics shops also sell catfish, which you can order online and deliver to your location alive. 

To add catfish into your fish tank, place the bag of unopened fingerlings inside the tank to allow the fish to adjust to the change in water temperature. Leave the bag unopened for a few hours or overnight, then open the bag to allow the fish to swim into the tank.

Caring for Aquaponics Catfish

Catfish are ‌a hardy fish species, which gives you some leeway while establishing your system. They can tolerate a wide range of environmental conditions, perfect for aquaponics if you have little experience raising fish. For healthy and happy catfish, feed them with high-protein fish food and monitor and maintain your system's water quality. 

Make sure also that the filtration system of your system is keeping up with the needs of your habitat, and keep in mind the fish to plant ratio. This will ensure that your plants are receiving enough nutrients. 

How to Breed Catfish 

If you plan to breed your catfish, place fine gravel at the bottom of your fish tank to achieve murky water. Then place three female catfish for every two male catfish in the tank. The more catfish you put, the more chances of successful breeding. Ensure that your water temperature is between 75°F to 80°F to encourage breeding. 

Catfish build nests for females to lay the eggs. The males then spray the eggs with sperm to fertilize them. The eggs will hatch in about ten days. The male catfish will guard the eggs until they hatch and continue to guard them until they are a week old. 

Conclusion

Catfish are not the hardiest fish to raise in aquaponics systems because tilapia is hardier than catfish. However, it is still one of the best fish to grow in aquaponics systems because it tastes better than tilapia. The secret to a successful aquaponic system is to do research before deciding. So make sure to know the growing conditions of catfish to ensure your success.