zoas seriously not opening

[dandoozled]

They looks really good for what happened. I see what you mean about the reddish covering. Get your actual numbers for nitrates and phosphates from them. That will tell you a lot. If you have zero-it’s probably cyano. If you have some, it’s most likely something else.

yeah it's cyano, I've had it for several months now haven't really done too much about it yet

 

[rkpetersen]

The salinity swing probably bothered them.
Cyano or dinos growing on the polyps will also definitely cause them to close up.
Undetectable nitrate and phosphate isn't ideal; zoas don't like it and it will promote dinos.
Sodium nitrate is available in granule form, and there are several products for adding phosphate to tanks.
Do you dose iodine? Zoas generally appreciate some iodine in the water.

 

[dandoozled]

The salinity swing probably bothered them.
Cyano or dinos growing on the polyps will also definitely cause them to close up.
Undetectable nitrate and phosphate isn't ideal; zoas don't like it and it will promote dinos.
Sodium nitrate is available in granule form, and there are several products for adding phosphate to tanks.
Do you dose iodine? Zoas generally appreciate some iodine in the water.

I haven't dosed iodine no, but I checked my params at lfs today and was told that my calcium was actually at 340 and my alkilinity was 7