Originally Posted by Mebbid
Almost all of the corals will eat but the vast majority of their nutrition is acquired form the zooxanthelle that is living in them. A lot of people don't bother feeding their corals at all and they will take in whatever floating debris comes their way.
That may be true but if you're like me and had a reef tank with no fish then you wouldn't be feeding your fish and there would be no "debris for them to grab".
I've brightened and grown my corals substantially by adding certain trace elements and feeding them properly.