agree with mike about the bloat. i feed all of mine spirulina crumbles, krill (they love that stuff), NLS flake and pellets, and they like red algae flakes. about once a week they will get a frozen cube of brine shrimp or a cichlid mix . i try to give them a good mix of food.
i have tried to feed mine frozen slices of zucchini, yellow squash and cucumber (the guys in the 180 gallon tank) but they just arent interested and are scared..
the pleco however, thats a different story lol