I fed earthworms and Hikari sinking carnivore. When he was really tiny, I had to cut the pellets in half (LOL it's crazy to think of me doing that now, when he's the size he is). Anyway, don't worry about him moving on to other foods. I have no problems feeding fish filets, squid, shrimp, Massivore, Aqua-Stable, Algae Wafers, etc... He eats everything -- fear not!