You'll want to start out with small meaty foods. Plankton, Formula One, mysis, and enriched brine are good foods to start. Please note that brine shrimp are not the best foods to KEEP fish on, but it often will get them started. Once the fish associates you with food, you can try some other items like pellets and flakes. Mine was very finicky at first but will now eagerly gulp down just about anything I throw in the tank.