I feed them during the day. They have all "learned" that when the flow stops, they're going to get some food. I turn the flow off about 5 minutes ahead of feeding and they all open up. My 2 Sun Coral colonies do the same thing. Only fish I have to worry about staling food from them is my McCosker's Flasher Wrasse. He will be leaving soon when I upgrade though.
I feed mine every saturday morning when the lights are off. I do this so the fish don't steal their food as they do when lights are on (most of our LPS readily accept food with lights on but get robbed). I still have to bribe the cleaner shrimp with a piece of krill or else he will steal anyway. Feeding krill to 4 scoly's and 3 plate corals this way. I also use a baster to feed brine shrimp to trumpet & candy cane corals (which do not tend to accept food with lights on).