Mine love Hikari sinking pellets and algae pellets. They'll wait to see if I put those in the tank at feeding time before they look to eat anything else.
mine eat everything, veggies clipped, romaine lettuce, apple slices, sweet potatoes slices, earthworms, peas...anything and everything they try to eat. My large red hooks swallow/chew hikari algae wafers like M&M's