I have found my gorgonians to have very exacting water requirements, and they will simply not open up if params are off accepted norms by a marked degree. I'd start my analysis there.
I feed my gorgonians a mixture of cyclopeeze and phytoplankton. I've tried clyclopeeze alone, but the particles are quite large, and it seems that most of the polyps can't absorb them. My corals seem to respond best to a suspension of very fine foods.