I bought 5 from Mckenzie's Fish Farm and 2 survived to a little over 4 ft in a 18ft diameter kiddie pool with a 4ft fence around it. When I transferred to another destroyer, I tried selling then, giving them away with no takers. Hated to do it but, had a 'fish-fry' party before having to move to the ship.
They ate krill, plankton, salmon pellets, earthworms, bloodworms, Bshrimp, chopped squid, flake, chopped chicken/beef hearts... pretty much anything I threw in was investigated as a potential food item.