NLS small community fish pellets, crushed flakes, shrimp pellets, algae/veggie wafers (for corys but my GBR seems to like these too), spirulina sticks, frozen daphnia and bloodworms. I guess mine isn't too picky. I soak most food in a spoon of tank water so it will sink as soon as I pour it into the tank as most of my fish, the GBR included, prefer to eat from the bottom.