well im guessing the fish is around 2-4 inches. so id say u should feed him frozen bloodworm, brine shrimp , etc. stay away from feeders. as he gets larger, switch over to market shrimp. this should be in the cold water/ native section
Moved to the coldwater section. I would also start with bloodworms and krill when it is smaller. You should be able to train it to take pellets later. Let us know what the setup is and also the size of the fish.