I feed the tank, a couple of times a week, specifically to feed corals, including SPS.
Oyster Feast
Coral Frenzy
Frozen Cyclopeeze
Rods Coral Diet.
I just broadcast feed, dumping it in a high flow area, either a few hours after lights go out or a couple hours before lights come on.
I don't believe it's necessary to do this, but I do feel that the corals benefit from it. However, you need to make sure you're still able to keep your water quality up, otherwise, you're defeating the purpose and actually causing problems.