One colony of Zoanthids won't open!

[shallowreef]

I was noticing over the past 5 days that one of my Favoriate colonies of Zoanthids has slowly been closing up. I checked my water parameters and my phoshpates are a little high. But the rest of my corals are not affected by this like this one colony is. I don't see anything crawling over it and there are no snails visible on the colony.

I have been adding buffer to try and raise my alkalinity over the past 2 days and haven't seen any changes in the colony.

I also have some simple to keep SPS (montipora) and they all seem to be doing fine. I would assume that if my water quality was bad they would be the first to show me a sign. Also i have this piece sorta in direct flow with one of my TUNZES but to make sure that it wasn't a flow problem i shut that TUNZE off for two days and they only closed up more. What could it be? My water quality except for the phosphate and Alk is fine. Oh i also have these rather close to the light and have had them there for the past month and a half and i never had a problem. Whats going on??

 

[spongebob lover]

hmm it could be normal .... they might be just cleaning themselves as it takes them about a week to clean.
i'd wait before doing anything and if they don't open by next week ...then just do a lugols dip .

 

[shallowreef]

Anyone else have any suggestions?