Zoanthid melting

[305phins]

So my zoanthid (Jedi mind trick) wasn’t really opening just like two out of the 5 were opening. So I dipped it in coral rx waited a week no improvement. 2 days ago I tried dipping them in Lugols and now they look like this. Something coming out of the closed heads. Anyone know what it looks like or have any ideas ? Thanks

 

[Mr. Mojo Rising]

How are other corals doing? Can you tell us about your lighting and flow and parameters?

 

[EnterName]

I would say the stuff you are seeing is either:

1. an expulsion of waste and "unwanted" (e.g. dead) zooxanthellae, or
2. mesenterial filaments, which are part of the coral's digestive system. I'm not sure if zoanthids also use them as a defense mechanism and stress response like some other corals do.

Iodine dips are quite harsh on corals. That's why most products like Coral RX don't contain it. Iodine certainly kills a lot of organisms (harmful or not), but the coral and its zooxanthellae have to tolerate it as well.
In microscopy it's common to use a very dilute Lugol's solution to kill, stain, and fixate various specimens. This affects dinoflagellates like Symbiodinium spp. as well, which make up a significant portion of your coral's symbionts. Its effect is immediate and extreme, so I hope you diluted the solution very strongly before use.

Mr. Mojo Rising is already asking the right questions to figure out what the cause of the issue might be. A remote diagnosis of a "disease" is pretty much impossible, but parameter adjustment to prevent the issue from getting worse might be feasible.