Coral turning white

[SajmonPL]

Dear Collogues

Since few days one of my corals started turning white. Previously it was nice and purple with green polyps. One thing that have changed is that I started to add iodine and strontium. Dosage is 1 drop per 100L for each. I have 50L tank and I add one drop every second day. Will stop adding for few days days and see what will happen. What is your opinion on that. Thank you in advance for your comments.

 

[imprezareef]

Are you talking about the zoanthids? they are just closed up. Something is potentially irritating them.

 

[SajmonPL]

Are you talking about the zoanthids? they are just closed up. Something is potentially irritating them.

I think the name of this coral is different. Normally it looks as on the picture.