decay

Hello, I've had this Devil's Hand for a couple months now, and recently I've noticed that parts of it have begun to sort of droop on its side. Polyps are still extending, but it looks weaker than it used to overall. Parameters have remained stable, but I'm thinking of doing a partial water...

Can't figure out if this was a ca problem, precipitation for far to long or some kind of worm eating the coral. Heads look great eats at night. Coral makes me scared. Didn't notice until I was working on a clean up. In the photo the left branch is holding on by a thread