Some zoas closed others thriving?

[Redseadragon12]

Ok this is strange usually its an all or nothing phenom. But now I have about 50/50 open/closed. Looking at my tank I have probably 400 zoanthids different varieties. Some of them are thriving so happily and growing like crazy while the others are half open with short skirts like folded over. I know it can't be a lighting issue because it is happening at all depths and edges of the tank.

Salinity is 1.024
temp 81
alk 10
ph 8.3
ammonia 0
nitrate/nitrite 0
phosphate 0
ORP 350
Calcium 420
Magnesium 1200
adequate flow.
Four fish not bothering them
1 emerald crab and pepermint shrimp

 

[Redseadragon12]

Any Ideas? no changes to filters or media and I do regular 10% weekly water changes

 

[saintperez]

I've read Iodine has something to do with Zoas but don't have details for you.

 

[Redseadragon12]

Yes they need Iodine to thrive but they should be getting that from the water changes. But I don't test it. I have also treated zoas with lugols so I assume they get extra iodine from that when added back to the tank.

 

[Redseadragon12]

Are there any zoanthid keepers on reef central?

 

[m0nkie]

subscribed.. having the same issue. others are growing new heads but random single/double polyp zoas are closing and melting

 

[Redseadragon12]

subscribed.. having the same issue. others are growing new heads but random single/double polyp zoas are closing and melting

This is exactly what is happening I have tons and tons of 1-2 head polyps and they are 50/50 half thriving and half closing up and dying. All different types. smaller ones are particularly thriving like hornets and rastas while anything larger is closed or half closed with tentacles retracted.

 

[Redseadragon12]

This is a nano tank only 16 gallons but it has also RBTAs which I expect to be a gauge of water parameters and they are doing really well. also have other random soft corals doing fine.

 

[m0nkie]

This is exactly what is happening I have tons and tons of 1-2 head polyps and they are 50/50 half thriving and half closing up and dying. All different types. smaller ones are particularly thriving like hornets and rastas while anything larger is closed or half closed with tentacles retracted.

yup... and mine are still dying. I'm dosing 2 parts so all my parameters are spot on. I have some 3-6 polyps frags that would disappear in 2-3 days. Half would close.. then a few days later melt. The other half would follow..

yesterday, I saw another 2 healthy polyps frags (half inch in diameter) close up.. this morning it remain closed. willing to bet it will melt in a few days. these 2 frags have been with me for 2 months... didn't grow much, but looked healthy.

I thought some bug is eating it. I dipped some pieces that just closed up and put them on the sandbed. monitored at night.. no luck so far in finding the culprit.

I'm starting to wonder how healthy my zoas are when they are fully open.. maybe it's like a slow dying clam.. it would look normal and die within a day or two..

 

[Redseadragon12]

Yes to me it is like they have an infection with a similar clinical course as a cancer. They seem perfectly healthy on the outside until one day they just start closing up and die off. The first thing I see with mine is that the matt begins to turn an opaque white color on the edges then it spreads and soon after 1-3 days the zoa has melted away.

 

[reefwars]

have you looked for nudibranchs late late at night?

 

[DrAsTiC]

+1

Zoa eating nudis could be the culprit

have you looked for nudibranchs late late at night?

 

[Redseadragon12]

Why late at night? Is there a special way to search for them?

 

[m0nkie]

Why late at night? Is there a special way to search for them?

they come out at night to eat. it's hard to see them. they are a few millimeters big AND blend into your zoa's color while munching on them..

I searched mine 2hrs before lights go on with a red flashlight.. didn't find anything for my tank.

 

[reefwars]

Why late at night? Is there a special way to search for them?

because they are more active during the night and easier to spot when polyps arnt open

brush the polyps with your fingers to close them if they are open but they will always be on top of the polyp and they lay their eggs on polyp stalks

 

[650-IS350]

look for these predators.

http://www.coralpedia.com/index.php?module=Gallery2&g2_itemId=384