Silversides can be bought frozen which is better over live food. Fresh shrimp is great as well. I agree that most corals (with a few exceptions) and anemones get their nutrition from nutrients in the water and good lighting. I don't feed my corals but I do feed my anemones small bits of whatever is left over from feeding the eels. If there's nothing left, they go without and they are fine. They will catch food when you feed your fish and do fine on that. Lights and good water are the most important things to concentrate on.