They should be fine with almost anything you feed your other fish (flakes, pellets, sinking food, etc). I have 2 and they're pigs. They can tell very quickly when food has been introduced (by sight or other sense) and will get to the food, often before the fish. Mine will swim upside down at the surface in order to grab surface floating flakes, swim against the current to catch oncoming flakes, grab betta pellets from the surface or on the bottom, eat pellets, scavange, anything and everything. They are also great algae eaters so if you have some of algae, they'll have plenty to eat. They're great and fun to watch.