Unhappy zoas

[JReefaddict]

I’ve had a decent size cluster of wwc candy apple greens for awhile now. Noticed it started about a week ago that all of the polyps aren’t opening. I have been doing a 25g water chance every other week on a 100ish gallon system. Don’t have accurate test parameters at the moment. I’m leaning towards some sort of pest even though all I see is a tiny bit of gha around the polyps with a visual inspection. I’m going to dip them this evening but would like some input. No new additions have been made and these have been in there for over 6 months.

Only change is about a month ago I had made the jump from t5 to led but they appeared to be happy after the swap.

 

[James M]

Pics ?
If there is Lots of algae near them they will be irritated and won’t open up

 

[JReefaddict]

I wouldn’t say it’s a lot, there’s a few thin filaments. I will take some pics when I can. Here is a couple weeks ago:

 

[JReefaddict]

 

[Capitol Reef Corals]

What PAR are they in? I'd try moving them to low light higher flow area. Also, I find that zoas don't necessarily need large water changes regularly and that it might be harmful for them as they light established tanks with stable parameters.

 

[JReefaddict]

Not sure what par they are at. They are about 8” from the surface of the water, and the lights are hydra 26 hd 14” above the water set around 50%.

Going to be moving them down some. I’ve been doing large w/c to try and starve out an algae problem I’ve had. Normally prefer to do smaller

 

[JReefaddict]

Update: put them down on the sandbed, backing down on the w/c to 15g every two weeks.

 

[LilElroyJetson]

Without test parameters this is really hard to try to diagnose and provide advice. I really don't think your water changes are the issue, nor the light change. They don't look terrible but definitely not in great shape either. My best guess is that based on the green hair algae (which in itself may be irritating them) is that if you are having algae issues you probably have high phosphates and zoas are known to sometimes respond poorly to high phosphates. If you can get your hands on an accurate kit, test your nitrates and phosphates and let us know what you're getting.

 

[JReefaddict]

The gha has kicked my butt, to the point I was frustrated to the point of breaking the tank down and starting over.

I ordered some fresh test kits so we will see some numbers hopefully mid week.

 

[LilElroyJetson]

I would try to manually remove as much of the GHA as possible by hand with a siphon to suck it out and remove it, thus simultaneously removing some of the phosphates trapped in the algae, and using a tooth brush to scrub off the rocks to take care of what remains or what begins to repopulate. Hopefully it passes soon! Beautiful Zoas by the way!

 

[JReefaddict]

I’ve got it pretty much controlled. I figured out if you just let it grow way out, it would pull off pretty clean in large clumps. I’ve got it like 90% gone except for the little filaments on that frag and some other but each week is improving in that department.

Fresh Red Sea kit otw though so we’ll see what those numbers are