They are omnivores and require both veggies and meats.
Mine will eat just about any veggie piece I toss in, and I occassionally give her a small sliver of shrimp.
I feed mine sinking spirulina pellets and New Life Spectrum sinking pellets and Hikari shrimp mineral pellets.
I feed veggies at a two to one ratio over protien and only one small piece a day.
She lives in a tank at my office, which is why I keep commercially prepared foods, just for the convenience or I'd probably just feed her fresh or frozen food only.