Need help with zoanthids

[TheFish]

Hi about 3 days ago these zoas stopped opening up all the way and looked odd maybe deformed. The tank is fairly new maybe a little over 4 months now, so these zoas we're still growing on the plug. I noticed that there was a couple white sponges growing on the back and the side of the plug as well as what looked like a green opaque portion in between the polyps. I was worried due to the look of the polyps so I figured I would dip in peroxide, because I thought the green substance was algae of some sort. After I dipped and rinsed eye examined the plug and the green substance closely and tried to lightly clean off the green stuff it would not come off and felt very hard glass like almost. I am fairly new to the hobby and was hoping someone had an idea of what I might be dealing with. Up until this point this track was growing quite well I started with one, And after a few weeks I had nine beautiful King Midas on the plug. But now they're not looking so good. I will post some photos of the plug out of the water with the green substance. As well as what they look like before.
Thanks for your time

 

[DanH86]

Looks like green bubble algae. Can usually be pried off with tweezers.

 

[Ta2oodfreak]

Yep, that's bubble algae. Pop it off without popping it.

 

[TheFish]

That's what I thought too but it was incredibly hard almost glass like definitely not bubble algae. Although today it looks like the peroxide took care of it so maybe it was bubble algae and just a really weird form of it. But there was no bubble and no way of popping it that's for sure. Thanks for your reply if you have any other ideas of what it could be I'd appreciate it. I will post a photo of what it looks like today. If you zoom in you can see where the substance was it left an indentation like it was eating away at the flesh.