I had the same questions as an aquaculture guy and it was suggested by Dr. Dwayne Maxwell at the California Department of Fish and Game office in Los Alamitos that raising channel catfish was a better idea than raising Tilapia because Tilapia are quite sensitive to low water temperatures. These sensitive Tilapia cannot take low-temperature water because it is lethal to them as it approaches 50 degrees Fahrenheit and lower for any length of time. Channel catfish can handle a much wider range of water temperatures. Channel catfish can also go to large size, are tasty and have excellent conversion efficiencies (assimilation conversion efficiencies). The catfish can also handle low D.O. in their water and higher stocking densities. Channel catfish can also assimilate large amounts of low-quality substrates and can convert it to fish proteins very efficiently. Tilapia mossambica is not allowed to be raised in "hydroponic systems", but that species can be raised in ponds and/or pools. Tilapia mossambica is the only Tilapia species allowed to be raised in the County of Los Angeles, but if they are sold for money you need to purchase a $700 a year aquaculturist permit to be legal according to Dr. Maxwell. He is at the Los Alamitos branch of the California Department of Fish and Game. His number is area code (562) 342-7152. I would strongly suggest you contact him for further legal and aquaculture suggestions within the law as he is an expert aquaculture specialist and researcher and is in charge of legal aquaculture intrpretations of the laws regarding their "farming". I know it's a pain in the butt, but I am just trying to help you. I had to talk to him three times regarding these same issues, both legal and biological efficiencies and tastiness and suggestions for your specific system. You can't search all you want to know about aquaculture on the internet unless you have unlimited time.

I just thought of another way to go. If you like Tilapia I suggest you look at her website online take a two-hour intro or a longer intensive class on how to grow and harvest (and market) Tilapia from Tilapia Mama (her online/stage name) in San Diego. She sells Tilapia mossambica fingerlings and has developed a great system of aquacultured Tilapia raised in her backyard and hydroponically-raised greens (Lactuca and Crucifers) of various species raised in her front yard for local high-end local markets. You can buy ready-made working systems from her too or get plans to make your own. She is very friendly and helpful and environmentally-friendly and reasonably priced. We should have someone like her here in L.A. County. maybe that could be you.

Please let me know how you do.

Toward sustainability,

Best,

Dennis Pilien (562) 947-3979 h