What Fish Work Best in Aquaponics?
-by Colle and Phyllis Davis
Tilapia is the fish most used in aquaponics.
Tilapia prefer a water temperature in the low 80’s° F, the water can be fresh water, brackish water or even salty water, and they do just fine. They will thrive in water that can be dirty looking and still grow and be ready for eating almost anywhere in the world. (Salty water will kill plants when growing food in aquaponics.)
Most trout/salmon do not like water over 60° F at which point they begin to experience stress and become susceptible to diseases in warmer water. This means either the water must be cooled and heated each cycle, or the fish or the plants will be unhappy and not grow well.
Trout/salmon are also carnivores and are grown best on animal protein. Commercial trout chow contains fish meal as the protein source and that fish meal is from ocean harvest fish, depleting the ocean fisheries.
Catfish, which was our personal first choice, have a different problem. The fry or fingerlings are only available three months of the year (May, June, July) so there is no way for farm owners to consistently restock their fish tanks. Catfish grow quickly, they like warm water, they will eat almost anything, they taste good and are a hardy fish. But, stocking off season is impossible.
Perch are carnivores and eat bugs, crayfish and other animals to grow. This feed is tough to get in the winter months unless you grow them inside for some other purpose. Perch food is tough to get almost any time of the year. Perch taste sweet and are easy to work with but are difficult to find food for them.
Most crayfish and many freshwater prawns are cannibalistic and need to live in separate ‘apartments’ built in the tanks so they don’t eat each other. They are sometimes used in the tanks with other fish to clean up the bottom of the tanks. They are very hardy, but the housing for them is a problem.
That leaves the incredibly, tasty, hearty and adaptable Tilapia. They are very easy to grow, prepare, they taste great, grow quickly, and are available year round. They are herbivores and prefer plant protein and are very hardy.