Help my Candy Cane

[Tylt33]

Hi everyone! Im a relative newb to the saltwater world, and i dont know what is going on with my candy cane coral; a bunch of the outer heads are dark and shriveled looking, and at night they are barely sending any tentacles out. Water parameters are perfect, and my other corals and fish are flourishing. Any ideas, guesses, or help would be greatly appreciated!

[danch]

How long have you had it?
Is it near anything that would be stinging or getting into chemical wars with it?
What kind of lighting do you have and how far down is the caulastrea?
What fish do you have? Any suspected nippers (blenny, angel...)?