I currently have a 9" diamondback sturgeon (acipenser gueldenstaedtii), I bought it a little over a month ago for my 6000gal outdoor pond at 6.5" (extremely quick growth rate, second only to the beluga sturgeon). Right now I am growing him out in my 180gal. I have been feeding him sera sturgeon pellets as his main diet, with broken up massivore, jumbo bloodworms, and market prawn fed a couple times a week along with the sturgeon pellets. He has