Feed them until they have large stomachs at least twice a day until they are 6-7". It shouldn't take them long to reach that size, then you can feed once a day. At small sizes they are always hungry and I've seen them rip off tails (not just fins, but right into the meat which won't grow back and results in death). I try to feed mostly whole fish (guts and skeleton included; not just filets) as a staple with occasional shrimp, prawn, krill, crayfish, insects, and pellets. In the wild they eat mostly fish and seem to get the best growth with whole fish. Chopped frozen silversides work good for juveniles.
Good luck.