You don't need to feed your coral. It's showing the skeleton so its unhappy and protecting itself. Like the others have said, move it around and see if it starts getting better.
I had a few corals fade and show there skeleton, I've nursed them back.
I'd say but it on the sand bed, low flow and low light.
"When creating an aqua scape, strive for the beauty of imperfection, as its art and there is no wrong or right, it's left open for interpretation" James Findley