Some zoas not opening

[wunderlong88]

Hi! I have some zoas that are tightly closed, some that are barely open and one set that is is open just fine. It's probably 10-12 days that I've had the problem, I'm guessing. All the the other soft corals seem happy.

I haven't seen anything bothering them. No fish or inverts and I've been checking and watching alot. I haven't changed locations, lights or anything I'm aware of, except today I noteced the powerheads were a couple of inches lower than normal (from moving and cleaning) and not giving me as much surface agitation. I've moved them back up just now.

I have a 180 with 85 gal sump. It's been running since Jun 2025. I have lots of live rock and live sand from the ocean (Gulf Coast and Australia). I keep lots of fish and some soft corals and a variety of inverts.

I tested today:
Phosphate - .95 ppm (pretty normal for me, I feed a lot!)
Nitrate - 25 pm (same)
Ph 7.7
Kh 7.7
Salinity 1.024/1.025
Temp about 78

I don't dose anything or run anything but a sump full of chaeto and a protein skimmer.
I do about a 15% water change every 10 days, just did one a couple of days ago.

I'm hopeful the powerheads not agitating the surface enough will remedy the problem (not sure when that should make a difference if it does) but wondered if anything else seems suspect?

Thank you.

FYI - Photos have titles to help

 

[DIYreefer]

Have you added any new corals lately? That looks like a pest issue to me.

 

[wunderlong88]

Have you added any new corals lately? That looks like a pest issue to me.

No, I haven't added any new corals in 8 mos.

 

[Privateye]

I would do my typical peroxide dip. I've seen it work wonders and I've never lost any zoas to it.

50/50 tank water and hydrogen peroxide (the regular 3%) for 4 minutes. They may not open until the next day.

 

[wunderlong88]

I would do my typical peroxide dip. I've seen it work wonders and I've never lost any zoas to it.

50/50 tank water and hydrogen peroxide (the regular 3%) for 4 minutes. They may not open until the next day.

I can do that for some but others I can't get the rock out.

 

[Mr. Mojo Rising]

I'm also leaning towards a pest of some kind.

Maybe you can list your livestock, including the inverts?