White film covering Zoas

[Cheeze]

Hi all,
One of my Zoa frags developed a coating of white film or sponge over the past 2-3 days, and the Zoas can’t open. Right now it’s only on one patch, other Zoas are looking fine.
I tried gently scrubbing it off with a toothbrush (outside the tank) but it wouldn’t come off.
Introduced this Zoa over a week ago and was fine then until the past couple days.

Parameters:
Calcium: 457
Alk: 8.3
Mag: 1380
pH: 8.2
Phos: .02
Nitrate: 0
Salinity: 1.025

I figure I can’t save these now and will sadly be disposing of this frag, but was wondering if anyone knows (1) what it is and (2) what could have caused it?

 

[SeaworthyAquatics]

Try any dips? I'd guess bacterial but if it doesn't come off I'm not sure. Zoas handle peroxide dips pretty well and might get rid of it. Iodine might be worth a shot as well.

 

[shakacuz]

could be bacterial. nitrate is low as well, they could be melting due to this.

 

[Cheeze]

Thanks both! I'll try a peroxide dip if not too late, and also look into ways to raise Nitrate a bit if that that could be one of the root causes.

 

[SeaworthyAquatics]

Brightwell Neonitro is easy to use and works well for nitrate. Loudwolf Sodium Nitrate is cheaper and purer option, but have to mix it yourself.

 

[Dsimas]

Mine are doing this. Just one colony, the rest are happy. What became of yours?

 

[Cheeze]

Mine are doing this. Just one colony, the rest are happy. What became of yours?

Sadly never cleared, and after a while realizing it's not going to recover I presumed they did not survive. All my other zoas are doing great tho, so it was isolated.