Feed them small meaty foods like cyclopseeze. I turn off my pumps and use a turkey baster to float bits of food over them. It takes a min or two for them to open then I spot feed them withe the Baster. I feed a few corals like this after about five min I turn the pump back on. It takes some practice but try not to over feed. You can also feed a tiny pice of shrimp with long tweezers.