I have a fat sailfin that I got at about3" and he is now about 6" and he will eat as much as I put in the tank. I mean I could literally stand there and dump food in all day and think he would eat every bite. I feed him mostly 24 hour seaweed selects everyday but I do mix in flake, emerald entree, squid and angel formula. Try to give the seaweed everyday and he will literally grow in front of your eyes.