Zoanthid Help!

[masgatigata]

I've noticed some of my zoas are dying. They have these bubbles on them...some are just melting away. My parameters are all in check. I've added some new spa frags about 3 weeks ago. I'm wondering if I might have introduced something to the tank. Any help/advise would be appreciated!

 

[masgatigata]

View attachment 229962

 

[masgatigata]

Of course I sent the pic upside down. Here it is right side up.

 

[worm5406]

What are the parameters... Just wondering. Looks like strange growth.

 

[masgatigata]

Calcium:420
Phosphates: .04
Magnesium: 1320
Kh: 8.3
Nitrates/Ammonia: 0

I've recently begun using a GFO reactor to reduce my phosphates. I just read through some boards today that zoas can become succeptable to bacteria if phosphate levels drop too quickly. Maybe this is what's happening. I dipped all my frags today and they look better already. Keeping my fingers crossed that the dip did the trick.