Zoa Frag Closed Up … ?

[Water Wolf]

Good Afternoon,

Fairly new about about 7 months in, Tank running good, multiple zoas, Duncan, Paly, Acan and candy cane with CUC and a couple fish. One of the Zoas I got last week looked nice and vibrant for the first 3 days then closed 3 polyps, then next day all were closed. It has some “hairs” growing up through the closed polups. All other corals look great and open. I did a dip to try and get rid of whatever’s bothering it. Does anyone know what it is ? I thought maybe some green hair algae but it seems pretty stuck to it and I don’t think that would have caused it to close up and not come back…

 

[Mr. Mojo Rising]

The hairs look like algae starting to grow from what I can tell.
Dipping the frag in peroxide water will kill the algae. The zoa's will be closed for a couple of days but should open up.

 

[EnterName]

This can happen sometimes with new zoa frags. It might be the outer skin layer of those polyps, some biofilm, or like Mr. Mojo suggested algae.

Carefully losen a snail from somewhere and putting it on the frag, can be a very gentle way of cleaning it without dips, etc. The frag might stay closed for a while but if flow, light, and parameters are fine it will probably recover.

I've also used tweezers before, but this comes with the risk of poking or squeezing the frag. Whenever there is a risk of physically damaging Zoas I recommend gloves and eye protection. Just recently (Eastern 2026) there was another palytoxin-related incident here in Germany where someone lost 65% of their vision/eyesight in a very painful process just from touching their eye after fragging Zoas.