When i feed my lps. I turn off my pumps. Just place a mixture of coral food in the water. The food gets around the entire tank and the corals sense it and pop out the feeders. As for the favia they can have feeders for days after the feeding. There is still stuff in water they will pull out. I have had some send out feeders after a few hours of introducing them into my tank but some rarely see feeders. Just keep good water quality and it should be fine.