i feed mine. they grow awesome!
i've got goochsters and purple deaths, and a several others that i don't know the names of. goochsters eat well, and the purple deaths are flippin pigs! ime, the larger the polyp size, the easier it is to feed them, and the quicker they close in on the food.
feed mysis and a local reefer's brew, 2-3 times per week. the other days i feed flake, and they get whatever they can catch in the currents.