Try feeding 30 min after lights out, and do it with the baster. Make sure you have a very low water flow in the tank at the moment to facilitate feeding the coral. I would try to feed it Liquid Life Marine Plankton at LEAST every other day. I would also make sure it gets very bright light. As you may already know these (flower pot corals) are almost always doomed to a slow death due to its unique necessities. Hope this helps and good luck.
Lots of helpful info on these corals here:
http://www.goniopora.org