Need help with Paly!

[Spawn]

Hi all, my paly is dying quickly. I have no idea what might be attacking it/happening to it. The first thing I noticed going wrong was that some of the fringes started turning blackish and curling up. Within 48hrs, that patch of the rock was bare, and the blackening tips were spreading. I dipped it in fresh water thinking there might be a nudi eating it, but nothing came out of the rock. Over the course of the last 4 days sections of the polyps have melted away, showing a weird whitish almost fungal looking coating along with the blackening tips. Yesterday I dipped it in melafix&RO water for a few minutes, but only thing that out of the rock was a tiny arthropod, some dead polyps and other minor detritus. Does anyone have any ideas of what might be going on? Thank you so much (I do know there are a few aiptasia in there!)

 

[Spawn]

Hi all, my paly is dying quickly. I have no idea what might be attacking it/happening to it. The first thing I noticed going wrong was that some of the fringes started turning blackish and curling up. Within 48hrs, that patch of the rock was bare, and the blackening tips were spreading. I dipped it in fresh water thinking there might be a nudi eating it, but nothing came out of the rock. Over the course of the last 4 days sections of the polyps have melted away, showing a weird whitish almost fungal looking coating along with the blackening tips. Yesterday I dipped it in melafix&RO water for a few minutes, but only thing that out of the rock was a tiny arthropod, some dead polyps and other minor detritus. Does anyone have any ideas of what might be going on? Thank you so much (I do know there are a few aiptasia in there!)

Also, this is in a small 10gal tank, there are no fish just two hermits and some snails and a couple bristle worms. It's been healthy and running great for 6 months with no problems, 20% water change every 10 days. I am going to change my carbon and see if this helps at all