The Best Fish for Warm Water Aquaponics Systems

Fish are an essential component of an aquaponics garden. They supply all the nutrients that plants need to grow. There are many fish species to choose from. However, different fish have different requirements, mainly concerning water temperature. If you live in a warmer climate, it is essential that you select fish that survive in warm water temperatures to get excellent results. This article discusses the best fish for warm water aquaponics systems, and hopefully will serve as your guide in choosing the right fish for your aquaponics system.

Factors for Choosing Warm Water Fish in Aquaponics

There are several warm-water fish you can grow in your aquaponics system, and all of them have their own advantages and disadvantages. But the process becomes easier when you know what your system needs. Here are some questions you need to ask yourself in choosing your warm water fish.  

• Are The Fish For Eating or Not?

Are you planning to eat the fish you are growing in your system? Or will they serve as ornaments? If you're planning to eat your fish, you have to build your system around warm water edible fish like tilapia. Ornamental fish like goldfish are not suitable for eating, but they are easier to maintain, more resistant to diseases, and less expensive. Goldfish are also great for smaller or indoor aquaponics systems. 

• Fish Type and Maintenance Difficulty

Some fish species are hardy and easy to raise, while others are sensitive and costly to grow. If you don't want to spend a lot of time and effort maintaining your system, choose a hardy fish immune to diseases and parasites. 

• Size and Space Requirements

Your fish tank's size will determine the type and amount of fish that are suitable for your system. Make sure to learn the adult size of the fish species you are planning to raise so you can choose the suitable fish tank for them. Some fish require space to thrive, so be aware of the maximum adult size and habits of the fish you plan to raise.

• Breeding Habits 

Fish breeding habits are also crucial in selecting fish to raise in your aquaponics system. Some fish species don't reproduce in captivity, while other fish species like Tilapia reproduce easily and quickly. Sometimes fast producing fish species can create problems in poorly built systems and cause fish stocking density problems. You may need to have separate tanks for breeding fish to spawn and keep the young fish alive and healthy. 

• Fish Diet

Fish diets are one of the essential things to consider in fish selection for your aquaponics system. Fish requires the correct balance of proteins, fats, carbohydrates, vitamins, fats, and minerals to thrive. Fish food choice and fish food nutrient availability can affect the maintenance cost of your system. Depending on your fish, you can feed your fish with commercial fish feed or homemade fish food. However, special attention must be given to homemade fish feed because sometimes they are not balanced in the essential nutritional components needed by the fish.

The Water Temperatures in Aquaponics

Fish are cold-blooded animals, which means they cannot regulate their body temperature. To survive, fish depend on the changes in their environment. That is why maintaining the right temperature for your fish species is very important. The temperature range for warm water fish is 76°F to 80°F (25° to 27°C). If your local weather is not ideal for your chosen fish or if it gets too cold at night in your area, you might need to consider installing a water heater.

Five Best for Warm Water Fish Aquaponics

1. Tilapia

• Edible Fish
• Temperature Range: 27°C- 30°C (80°F - 86°F)
• Ideal pH Range: 6.5-9
• Suitable for tank and pond aquaponics
• Omnivores: only requires 22-35% of protein
• Fast Growth: 600 grams in 6-8 months
• Easy to Breed in the Fish Tank: every 4-6 months
• Hardy Fish: can tolerate pH swings, temperature changes, high ammonia levels, and low D.O.

Tilapia is one of the most popular and widely used fish in aquaponics. This hardy fish is excellent for beginners and small-scale aquaponics systems because they can adapt to their environment and withstand less than ideal water conditions. They are resistant to many pathogens, parasites and handle stress. They are omnivores, meaning they eat both plant and animal-based feed. 

The harvest time for Tilapia is between six and eight months, depending on how warm the water is, how much they are fed, and the size of fish you want to harvest. Tilapias are easy to breed in small-scale and medium-scale aquaponic systems. For an in-depth discussion on how to raise tilapia in aquaponics, click here.

2. Catfish

• Optimal Temperature: 75-86° F (24-30° C) 
• Ideal pH range: 7-8
• Hardy widely farmed food & Sports fish 
• It needs a large fish tank (250+ gallons) 
• Fast Growing: can be harvested within three months
•  Edible: Catfish are rich in Vitamin D
•  Excellent Feed Conversion Ratio: 2lb feed/ lb fish

Catfish are a highly hardy group of fish tolerating wide swings in D.O., temperature, and pH. They are also resistant to many diseases and parasites. Catfish are the easiest fish to raise for beginners in aquaponics who want to grow fish in locations where the electrical supply is unreliable. Because of their high tolerance to low D.O. levels and high ammonia levels, catfish can be stocked at a higher density, provided that there is enough mechanical filtration.

Catfish are benthic fish, meaning they are bottom feeders and valuable scavengers that are not territorial and easy to breed and raise. When raising catfish, it is recommended to use a tank with more significant horizontal space than vertical space to allow the fish to spread out at the bottom. Other fish like Tilapia, Perch, or Bluegill sunfish can be raised with catfish in the tanks. They grow relatively fast and can be harvested within three months. 

3. Jade Perch 

• Originated in Australia
• Optimum Temperature Range: 70°F - 80°F (21°C - 27∙°C)
• Ideal pH Range: 6-9
• Edible 
• Stocking Density: 1 pound of fish for every 10 gallons of water
• Fast growth: 500g in 10-12 months
• Do not breed in captivity
• Omnivorous: needs medium protein diet

Jade perch is a hardy fish and versatile fish. They are ideal fish for beginners in aquaponics because they can tolerate a wide variety of water conditions. Jade perch is full of nutritious oils that provide a range of health benefits. They are also easy to grow and can be harvested within a year, making them a perfect fish for your farm-to-table setup. However, aquaponics growers in some countries may have problems purchasing jade perch fingerlings because they are native to Australia and may not be available in some countries. If you want to grow jade perch in your aquaponics system, you should first check your local fisheries department to know if they are readily available. 

4. Largemouth Bass

• Optimum Temperature Range: 70°F-86°F (20°C-30°C)
• Ideal pH Range: 6-8
• Minimum Tank Size: 1200 gallons
• Carnivorous: requires 40% protein diet
• Edible: with high levels of omega-3 fatty acids
• Can be harvested within one year from fingerlings

Largemouth bass can tolerate a wide range of temperatures, low D.O., and pH. However, largemouth bass prefer clean water. They are carnivorous fish, and they require a high protein diet. The growth rates of largemouth bass are dependent on the temperature and feed quality.

I obtained most of the growth during the warmer season in temperate climates because of their high D.O. tolerance and resistance to elevated nitrite levels. The largemouth bass is one of the best fish to raise for aquaponics growers, particularly those who cannot change fish species between cold and warm seasons.

5. Barramundi

• Optimum Temperature Range: 74°F - 86°F
• Ideal pH Range:6.5-7.2
• Requires high concentration of Dissolved Oxygen
• Carnivorous and highly predatory fish
• Feed at least three times a week

Barramundi is another excellent warm water fish for aquaponics because of its hardiness and rapid growth rate. Many aquaponics growers, especially those who live in warmer or tropical climates, still prefer to grow barramundi because of its fast growth rate. However, barramundi is not an ideal fish for beginners in aquaponics because they have different water requirements. Barramundi grows so fast that it can grow to one kilo in just seven months. 

Conclusion: What is the Best Fish for Warm Water Aquaponics?

Choosing a fish for your home aquaponics system can be exciting as there are many fish species to choose from. But before going further into choosing the best fish, you need to take note of your climate and water temperature as it affects what variety of fish is the best for you. The best fish is the one that is readily available and suited to your climate. So, if you live in warmer weather, choose a fish that likes warm water temperature.

However, even if you live in colder climates, you can still grow warm water fish species, provided you use water heaters to keep up with the temperature fluctuations.

Hopefully, this article has provided you with some ideas on what fish to raise in your aquaponics system. Thank you for reading, and always remember to have fun experimenting with your system and enjoy all the benefits of aquaponics. If you’re new to aquaponics, read our article, the ultimate aquaponics beginner’s guide.