sick coral

Has anyone had a Zoa colony do this? It looks like the polyps are melting and turning brown. I have looked carefully for pests and visually there is nothing to see. They are just slowly melting away. Any advice on how to save them?

I bought a pretty big purple candy cane colony a couple weeks back and for the last week the tissue has been receding on a few heads and it hasn’t been plumping up like it was when I first got it. Does anyone have an advice on anything I could do to possibly help it recover would be greatly...

It's me again... I feel like I need a dunce hat ;Sour with this scoly I'm trying to salvage. I posted last week to ask about a hitchhiker which turned out to be just a sponge (ty @Crabs McJones)....but now I've got these super weird string looking growths?? I've never seen anything like them in...