One zoa group closed up

[Bribo12]

Hey guys I’ve had a bunch of different zoas for about 1.5 months in my tank some newer some older. All have shown nice growth and growing new polyps. The fastest growers were these nirvanas I got. They went from around 6 heads when I got them to about 16ish now in about a month. However for about the past week and a half they have been like half to 1/4 open with the smaller polyps not opening and some algae on them. I’ve got 5 other varieties right nearby that are all open and growing. I checked for nudis/pods but don’t see anything. They are in a 20 gallon about 16” under an AI hydra 26hd.

parameters
Salinity 1.025-26
Temp 79-80
Ammo, trite 0
Nitrate 10
Phosphate 0.06
Mag 1500
Calcium 480
Alk 8.3-8.5
pH 8.3-8.4

I’m wondering if I should just let them ride it out as just growing pains since the tank is only about 3 months old or if there is something else to do

 

[LxHowler]

Have you made any changes to the tank recently? Any changes in flow of light ect. Sometime mine do just close up for a bit and then reopen. It's still a pretty new tank so I'd resist moving them and let them adjust to anything that could still be changing. If they are still opening a little bit then they are still alive.
Where abouts in the tank are they. You say in a cube, if they are on the sandbed then it could be that they have got sand on them. Mine close up whenever they get sand on them. I'd also try to blow any algae off of them as this will be irritating to them

 

[Bribo12]

They are on a rock that’s on the sandbed. I did just blow the algae off when I did my wc yesterday. I added an ato about 2 weeks ago but haven’t seen a change in salinity or temp. I also bumped my light intensity up some but did that over the span of about 2 weeks as the tank is mostly SPS dominant. I have other corals (Hammers, acros, Duncan, stylophora, birdsnest) all doing great and growing. I’ll post pics of the culprit coral after I get my daughter down for her nap. Thanks!

 

[Quietman]

Sounds like you had a great start with them. You said some algae, some is ok but too much can bother zoas preventing fully opening. Also depends on what type of algae, but I'll assume normal GHA. Might want to look into managing that a bit without changing too much from the good start parameters plus everything else is doing well. Meaning I'd go with clean up crew rather than any product dosing or parameter changing as your numbers are good for zoas.

Astrea snails are very good at eating the algae from between polyps without damaging the corals.

Edit: And sometimes, they just close up for a bit...days or weeks sometimes, then open up and off and running again. Not sure why that happens. I try not to overreact. Zoas are definitely NOT the canary corals in my tank.

 

[Bribo12]

Here’s a comparison pic

thanks, yeah idk my other zoas look fantastic lol

 

[Quietman]

Here’s a comparison pic

thanks, yeah idk my other zoas look fantastic lol

Oh...didn't know it was just one group. I'd wait it out. Changing light, blowing sand/algae can all irritate corals. The others look too good to mess with anything.