I can't tell what species you have. Most Gorgonians are non photosynthetic animals and require planktonic foods added to the system to stay alive. What, if anything are you feeding? Also, I've noticed Gorgonians are highly susceptible to various kinds of algae growing on them...it interferes with their feeding. To keep most Gorgonians, you really have to keep the PO4 & NO3 down, and of course heavy feeding makes this a challenge. good luck.