I have 2 goniopora. One will grab small particulate food and one does not (just gets organics from the water column I believe). I think one of the keys to keeping them is to provide plenty of organics/food to them yet still keep water quality high. This is where coral stim seems to help out, although you could achieve the same without using coral stimulator. I don't remember where I read it but somewhere I read that goniopora are one of the species that tend to dominate reefs in areas close to sewage discharge due to the increased levels of organics in the water.

That is an alveopora in the pic. Usually much hardier than goniopora but the care is similar. The article below, the guy is seeing good results from feeding them DT's oyster eggs. I have never seen alveopora take items as large as cyclopeeze/daphnia/baby brine etc.

http://reefkeeping.com/issues/2005-10/nftt/index.php