One of my corals (the big pavona) has a little area where the polyps are disappearing down to the bare white skeleton. I've been watching for about 3 days and unfortunately it does look like it is slowly spreading. I pulled the coral out and just finished a 20 minute dip in a dilute iodine solution. I broke off most of the newly bare areas and I'll keep my fingers crossed. Anyone else every experience this with pavona's? Any thoughts?