Tom Willis wrote:I'm trying to move as close to off grid as possible and I'm considering aquaponics as a way to provide fish for us since I don't have a good place for a pond. Since I'm mainly interested in the fish as I have other areas of my property for growing, all the plants the fish help grow could be fed to the fish in return. If there was surplus leftover for us, that would be great, but not necessary.
My main questions:
1. How viable is aquaponics as a closed loop system? I've heard of growing insects, plants etc. for the fish, but is this truly enough to account for 100% of the food the fish would require? Is it sustainable year around? Can I raise some fish as food for other fish?
Tentatively the answer is yes, but I have to say a lot depends on location. Warmer your location the easier it is. For example one could raise Talipa using a vegetable diet during growout. Problem is if you live in Minnesota Talipa is not a good choice because below 50 degrees they will tend to die out. Then your choice might be Perch which is a pure carnivore requiring fish meal pellets. A good choice for raise your own feed is mealworms. Dried its about 50% protein
2. I'd like as least input as possible, so heating the water would be off the table for me. I live near the Dallas area, so I'm curious what fish I could consider using in my area?
Talipa as a summer growout. Harvest before November comes around. Alternate would be catfish. Any of the native species could be done as well -- brim, bass, carp.
3. If done on small scale, could pumps be avoided? I mean once or twice a day go manually scoop out the water from the fish tank and feed the plants. Or any other idea to avoid electric pumps?
Typical aquaponics practice is to have at least two turns of water exchange thru the filters and growbeds every hour. Even a small system of 275gal (a single ibc) means you have to slop around 1 ton of water every hour. Just not practical.
4. I'm interested in how many fish could be raised in a certain sized area, sustainably. I'm also interested in learning about how many fish can be produced for meat by a said number of fish. I have no idea about how many babies a fish has and how many times per year etc. and if that is effected by keeping fish in this rather unnatural condition. Can someone explain to me or point me in the right direction of getting such information.
General rule (hence its danger) is 1 cu ft of water per kg of fish. That can vary widely by temperature, species grown, feed used, density and type of plants in growbeds, etc. A 'formal' source is the University of Hawaii has a online course on Udemy $99. A very good source on YouTube is Rob Bob's Backyard Farming -- https://www.youtube.com/user/bnbob01
A general caution about Aquaponics is that unlike dirt growing, you the operator have to juggle all the various variables to maintain the fish and plants. Might suggest trying hydroponics on a small scale first just to develop the proper management practice. Once mastered, the aquaponics piece can be 'plugged in'.
Thanks in advance