Zoas shrinking and po’d?

[RedFrog211]

The frag has been here for months, growing well. All of a sudden, it seems to be shrinking and closed. I have fed them 4 days ago, weekly water changes, etc. Lights have not changed.

Parameters:
SG: 1.026
Temp: 79°F
Mag: 1400
DKH: 10
pH: 8.2
NO3: ~ 3

photos are 3 days apart.
There are 3 fish in the aquarium, 2 ocellaris and 1 molly, and clean up crew consists of snails and crabs, though the coral are on frag racks, and are inaccessible.

 

[vetteguy53081]

If it API kits you are using- there is a high likelihood you ARE GETTING FALSE READINGS. So lets skip the speech on water and talk about zoas. Zoas must have iodide, not iodine in their water and under moderate light and water flow. They seem to do best in the lower half to third of the tank in an area of low-medium to medium-high flow. Too much flow may make it hard for the polyps to open. You will know your zoanthids are ‘happy’ if they open up and are fully extended without seeming to stretch so far upright.. The majority of zoanthids have symbiotic photosynthetic zooxanthellae (I dare you to try and say that three times quickly) and are therefore best kept with at least moderate aquarium lighting as mentioned for production of zooxanthele.
Zoanthids require the standard water parameters that are good for keeping just about any of your corals healthy. You’re aiming for water temperature about 78 F, salinity somewhere around 1.025 specific gravity) and normal hardness 8-11 dKH) and a pH around 8.1-8.3.
However, if your polyps were previously open and have recently closed up, this should be taken as a serious sign of a water parameters issue. The first things I would check are ph and salinity. In my experience, zoas will close up if there are swings in salinity.
You can also try a hydrogen peroxide dip and inspect the underneath of the plug to assure no bugs are underneath

 

[RedFrog211]

If it API kits you are using- there is a high likelihood you ARE GETTING FALSE READINGS. So lets skip the speech on water and talk about zoas. Zoas must have iodide, not iodine in their water and under moderate light and water flow. They seem to do best in the lower half to third of the tank in an area of low-medium to medium-high flow. Too much flow may make it hard for the polyps to open. You will know your zoanthids are ‘happy’ if they open up and are fully extended without seeming to stretch so far upright.. The majority of zoanthids have symbiotic photosynthetic zooxanthellae (I dare you to try and say that three times quickly) and are therefore best kept with at least moderate aquarium lighting as mentioned for production of zooxanthele.
Zoanthids require the standard water parameters that are good for keeping just about any of your corals healthy. You’re aiming for water temperature about 78 F, salinity somewhere around 1.025 specific gravity) and normal hardness 8-11 dKH) and a pH around 8.1-8.3.
However, if your polyps were previously open and have recently closed up, this should be taken as a serious sign of a water parameters issue. The first things I would check are ph and salinity. In my experience, zoas will close up if there are swings in salinity.
You can also try a hydrogen peroxide dip and inspect the underneath of the plug to assure no bugs are underneath

Tests are Hanna and Salifert- flow is rather minimal, (though not absent) and light is moderate. It was such a sudden deterioration, so it was alarming, though I’m hoping it’s just them expelling water due to the recent water change. Thank you for your time @vetteguy53081

 

[Zoa_Fanatic]

Tests are Hanna and Salifert- flow is rather minimal, (though not absent) and light is moderate. It was such a sudden deterioration, so it was alarming, though I’m hoping it’s just them expelling water due to the recent water change. Thank you for your time @vetteguy53081

Mine did this and a UV sterilizer stopped the issue. I can only assume it was some type of bacteria or virus.

 

[mdb_talon]

Tests are Hanna and Salifert- flow is rather minimal, (though not absent) and light is moderate. It was such a sudden deterioration, so it was alarming, though I’m hoping it’s just them expelling water due to the recent water change. Thank you for your time @vetteguy53081

If you want the whole article Vette's copy/paste came from here it is.

Zoanthids coral care, placement, feeding, and advice

Zoanthids coral are an extremely popular soft coral species. Learn more about how to care for them in a reef tank, including placement & feeding

www.saltwateraquariumblog.com

 

[SDK]

High phosphate levels can cause Zoanthids to shrink like that, and I notice that you did not provide a test result for that parameter.

If you are not currently testing for PO4 I would make checking into that a priority.

 

[vetteguy53081]

Tests are Hanna and Salifert- flow is rather minimal, (though not absent) and light is moderate. It was such a sudden deterioration, so it was alarming, though I’m hoping it’s just them expelling water due to the recent water change. Thank you for your time @vetteguy53081

Also try gentle bursts with a turkey baster