HELP! Whats up with my candy cane?

[Enigma]

It looks like its mouth may be gaping a bit. I don't know that I'd be overly alarmed, yet. Your nitrates are high, IMO. I personally wouldn't let them climb above an absolute max of 5ppm in a reef tank.

How often do you feed the candy cane?

I recently read (I don't remember where) that over feeding LPS can result in the flesh growing faster than the skeleton. If the skeleton can't support the flesh, some of the flesh dies off. I don't know if that is true or not, but it is something to ponder.