People often ask me about the types of fish that I recommend for aquaponics systems. Most sources recommend tilapia. I think that the best choice depends upon the climate where you live and your personal values.
Most of us are aiming for sustainable food production. My interpretation of "sustainable" means that it is efficient based upon what I put into my system vs what I harvest from it. I want the greatest yields with the least resources.
If you are in the Pacific Northwest (like me), then tilapia is clearly a poor choice. Tilapia do best when the water temperature is in the 70s. The temperature in my systems usually dips into the 50s during cold winter weather. Sometimes, the power goes out during a storm; heaters fail; or circuit breakers and gfcis trip and the water gets cold.
Why not choose fish species that are adapted to your local climate, so that you don't have to worry about your fish dying when the weather gets cold? I've raised black crappy, brown bullhead catfish, largemouth bass, and bluegill. I've found that the catfish and the bass do the best in recirculating aquaculture systems and aquaponic systems.
During the winter months select crops that will grow well in cold temperatures such as kale or collard greens. As the weather warms adjust your crops accordingly. Local fish species will do just fine as the temperature climbs. Just make sure that you filter and aerate your water sufficiently.
Sustainable aquaponics gardening means that that you go with the flow, so to speak. Adapt to your climate and you will have the best results at the lowest cost to both your wallet and your environment.