Hand feeding already, thats great. Looks like u got a good one. Ours always swam to the bottom. Anyways, dont throw all of them into the tank. I have found this to stress the fish out, well, at least ours. I use to throw in either 4 large goldfish feeders or like 8 small goldfish feeders. BUt keep in mind, this was at my store, not a 55 gallon. It really all depends on how big he is and how much of an appetite he has lol. For now, throw in 10-15 and see how fast he goes through those.