Zoo Question

[Mr.First]

Yesterday one of my Zoo frags (about 30 polyps) about 5 to 10 of them kind of melted away. I cut them off. All seemed okay. I come home from work and the remaining good ones look like they are taking a dump. There is like 1/4" long brown threads coming out of the centers.
Any suggestions or ideas what this is , or should I do anything?

 

[Deanos]

Did you recently change your lighting? It sounds like your zoanthids are expelling their zooxanthellae.

 

[scarf_ace1981]

have you tested your water parameters recently?