It doesn't quite look like BJD, so I don't think you need to do anything rash right now, but if it truely were BJD, I wouldn't wait until your next water change. If it starts looking worse/spreading or you are able to suction up any of the "jelly", I would pull the coral immediately- on torches, about half of the heads I've tested seem to die in under 24 hours from first symptoms. Here's a write up for a step by step procedure if it turns that way: