The Most Frequently Asked Question is “What’s the Best Fish for Aquaponics?”
by Colle and Phyllis Davis
The most often asked question in aquaponics after, “How does aquaponics work? What fish can be used successfully other than tilapia?” The vast majority of aquaponics installations in the Northern Hemisphere use tilapia because they are readily available year round, they’re a healthy fish that grow quickly, convert feed very effectively into body mass and are very easy to raise.
Phyllis Davis Explains Tilapia Fish that are Used in Portable Farms®
There are some jurisdictions in which tilapia are not allowed. This is because they are so prolific in increasing their numbers that they displace native fish if allowed into the wild. PFAS LLC has passed on millions of dollars of business because the California Fish and Game Dept only allows, under specific condition, the possession of tilapia in the six most southern counties of the State. In the rest of the State, tilapia are banned by the Fish and Game Department and are considered illegal, and the cost to the perpetrator is a nice round $10,000 PER FISH in violation fines. Fish and Game are very serious about banning tilapia because of the severe shortage of water in the state and their need to protect the rivers, ponds and streams.
What other fish can be used in aquaponics successfully in aquaponics?
Catfish is our personal preference because they taste great, we grew up eating catfish, they grow fast and are very easy to raise. The single problem is the fry or fingerlings are only available three months during the late spring each year (May, June and July). This inflexible supply of fish requires a batched system where all the fish are the same age and have to be harvested at about the same time. This leaves the systems with fewer and fewer fish near the end of the annual cycle.
Koi are a wonderfully easy fish to raise. The fingerlings can be obtained year round, they grow fast, they are beautiful and no one eats them. They are the perfect ‘poop producers’ because their gut is very ineffective and they eat and poop constantly. There is a market for the most unusual and most beautiful specimens of koi but again, no one eats them. If you only want poop, these are a great choice or if you are a vegan and want to name them as pets, koi are your answer.
Goldfish, yep, the little feeder goldfish you buy in the pet store for a few cents each can be used in aquaponics. You need five to ten per gallons of water instead of one, as with tilapia, because they are so small and grow relatively slowly and never grow too large in size. The problem? What do you do with them? Eating them is out, selling them is unprofitable and so you will simply have to keep them for a long time. Eventually you will have to start removing some of them from the system because they are prolific breeders also. Putting in a few bass or perch or even some catfish might work too.
Salmon/trout are a slight possibility if raised in cold climates. The fingerling problem is similar to the catfish in being seasonal. The systems for these fish requires a double heat exchanger arrangement and there needs to be an inexpensive source of electricity because the water has to be first heated and then chilled each time the system cycles.
Carp work extremely well but they have the same limitations as koi without the possibility of selling the cute ones. Some ethnic markets will buy all you can produce, check your markets to see if there is one nearby.
In Australia they use white perch and barramundi in their system very successfully. These fish in most cases cannot be imported into the US and Canada.
Crayfish and shrimp are both detritivores and some of them are cannibalistic and present the operator with different challenges. Yes, they can be raised in aquaponics successfully. Some people use them to help keep the bottom of the fish tanks cleaner and add a tiny bit of revenue to their operation.
Our choice is tilapia – a fast growing, healthy, easy to obtain in most places and with an unlimited supply of fingerling year round. That is spelled TILAPIA.