Since he is new to the tank, I would give it more time. I feed my crabs...emeralds and porcelains....dried algae, Iko-Wakame, that I get from the asian store, and shrimp pellets. They are usually hanging around one particular area, so finding them is easy. Just drop the pellets in that area and they will find it. My shrimp eat the same things too. But to be honest, you shouldn't have to feed him everyday...there is enough algae and dietrus in the tank for him to survive.