...Having Some Issues With Zoa Growth

[jackthestrat]

Hi guys.

Lately I have been having some issues with zoas in my tank. I have had a few "designer" frags melt on me, which I guess is pretty common. Most worrisome is that I have several colonies of zoas that appear to have simply stopped growing. In fact, they look like they are literally shrinking - not because polyps are disappearing, but because the polyps are shrinking in diameter and are growing closer together.

Current params:

ALK: 8
CA: 430
Temp: ~79
pH: 8.2
Mag: 1200
Nitrates: 0
Phosphates: No Clue

Current setup: 6x39w ATI Powermodule, 4x blue+, 1x Fiji, 1x AB special
No Carbon, No GFO, NP Biopellets
ITech Model 100 Skimmer
Kalk top-off for ALk/CA supplementation
2x tunze 6055, 1x 6045 for flow

Feeding regimen: heavy pinch of pellets twice a day, ZeoFood (3 drops twice a week).

I have not added any new livestock to my tank for over 3 months. My other corals, especially my SPS and my acans, are growing like crazy, with healthy polyp extension and excellent coloration, etc. I raised the PM unit to about 8" off the surface of the tank in case there was some photoinhibition going on, I just did that this weekend.

I have looked for snails and have not found any, to the best of my knowledge there are no pests whatsoever in my tank. There is a touch of bubble algae and a few aiptasia. This issue has been going on now for almost a full year, long before the biopellets went on the tank.

Any thoughts?

 

[Joel A]

no thoughts on the zoas.. except for the fact that zoas suck any sometimes they just simply don't grow and waste away for no reason.. they seem to like dirtier tanks?

Question though, how do you like that bulb combo? That was going to be the bulb combination next time i replace bulbs...

 

[Dekon]

I also would like to see if someone has an answer to this. I had about 10 frags of zoas that started out as 5-10 polyp frags and quickly grew into 60+ polyp colonies, then they did the same thing as you described. I have none left, not even 1 polyp. Everything else in the tank looks great. I searched looking for pests, at night I even used a red flashlight to look around and never spotted anything. I also do not think it was zoa pox becasue I did not have any of the white spots on the polyps normally associated with it. All of my palys are fine. I am still just as confused as you are.

 

[jackthestrat]

no thoughts on the zoas.. except for the fact that zoas suck any sometimes they just simply don't grow and waste away for no reason.. they seem to like dirtier tanks?

Question though, how do you like that bulb combo? That was going to be the bulb combination next time i replace bulbs...

I like the combo, but its kind of blue. I like whiter tanks though, I used to run a 6500k Daylight instead of the 4th blue+ and thought it was purrrrfect.

Yeah my tank is pretty far from dirty so I'm not sure if maybe lack of nutrients is hurting me here?

 

[pillowfish]

Matt, you can always put them in my tank again and let them grow like weeds

Zoas I think are just one of those things that there is no concrete answer on, you may be lacking something they need or they just get to a size where they self destruct? The growth pattern changing may be a flow or light issue? Smaller and tighter groups I would think would be a sign of some type of water change. Not too sure, I am really not a big zoa person as everyone I have ever put in my tanks has taken over everything

 

[gweston]

I haven't quite figured it out either. My params are very good as well (alk is around 10dkh). At the moment most of my Zoas are doing well, but one small colony has been 'iffy'. The others are fine. Growth has varied. A few colonies grew like weeds. A few others not much.

I keep mine with moderate flow and lighting. They do seem to like when I supplement vitamins a bit though. I have been using 'fuel' and occasionally dosing strontium/molybdenum. But not often at all... as in maybe a bit every few weeks. I recently dosed and they do seem a tad happier but it could be circumstantial. I use A&B two part for alk/ca, but when only dosing calcium, I have been using purple up instead.

One consideration is to read up on 'Zoa Pox'. But.. it seems they can be finicky even if they don't have the so-called Pox. It seems one person found out that you can treat for the pox. I don't recall the med used. I think it was an anti-fungal. There is a post out there on it somewhere on it.

 

[frank180reef]

mine stopped dieing when I took them out of strong light

 

[stingythingy45]

I've heard of some hobbyist having good luck with vitamin C dosing for zoas/palys.
I have a bunch of RPE's begin to close and look bad.Just couldn't find what was wrong.Then a week later I notice this small tube in the middle of them.It was a vermitid snail,and the thread it sends out was bothering the paly.
Odd thing is,the vermitid was bothering them even before it's tube was visible.

 

[jackthestrat]

Matt, you can always put them in my tank again and let them grow like weeds

Zoas I think are just one of those things that there is no concrete answer on, you may be lacking something they need or they just get to a size where they self destruct? The growth pattern changing may be a flow or light issue? Smaller and tighter groups I would think would be a sign of some type of water change. Not too sure, I am really not a big zoa person as everyone I have ever put in my tanks has taken over everything

I've even tried some water changes in case there was some mysterious element that I was missing. Didn't help.

 

[jackthestrat]

I haven't quite figured it out either. My params are very good as well (alk is around 10dkh). At the moment most of my Zoas are doing well, but one small colony has been 'iffy'. The others are fine. Growth has varied. A few colonies grew like weeds. A few others not much.

I keep mine with moderate flow and lighting. They do seem to like when I supplement vitamins a bit though. I have been using 'fuel' and occasionally dosing strontium/molybdenum. But not often at all... as in maybe a bit every few weeks. I recently dosed and they do seem a tad happier but it could be circumstantial. I use A&B two part for alk/ca, but when only dosing calcium, I have been using purple up instead.

One consideration is to read up on 'Zoa Pox'. But.. it seems they can be finicky even if they don't have the so-called Pox. It seems one person found out that you can treat for the pox. I don't recall the med used. I think it was an anti-fungal. There is a post out there on it somewhere on it.

It ain't the pox. These guys seem perfectly healthy, just the polyps are shrinking in diameter and the colony is not spreading at all.

 

[joefish]

Move the zoas to a different location in your tank, that mite help.

 

[dcforester1]

I have been going thru the same thing for about 6mo. I have 2 diff kind not relly open, and stay almost closed, and then another group are growing like crazy.

 

[The Ng Thing]

is it possible that they are just dying of old age? I don't know zoa's very well.

 

[dz6t]

Zoa eatting nudibranch?

 

[jackthestrat]

Zoa eatting nudibranch?

I suppose it is possible. Though the number of polyps isn't really declining - just their size. I'd expect polyps to be consistently disappearing if there was a pest issue.

 

[gweston]

Another consideration is they are being bugged by pods. I had some pods that would munch on my palys (zoas to a lesser degree). The same type even burrowed into the base of my toadstool leather to make a 'cave' for itself. It was quite destructive!

I got sick of manually pulling out corals to remove the pods. Since adding six-line wrasse, the problem has effectively been eliminated. The toadstool is growing like mad and the paly is healthy again. So far the wrasse is a very good citizen, and even plucks parasites from other fish to my surprise.

I took a pic of the pod if you are interested... I can dig it up and post. It was a large amphipod with rather large hook-like claws.

 

[jackthestrat]

Another consideration is they are being bugged by pods. I had some pods that would munch on my palys (zoas to a lesser degree). The same type even burrowed into the base of my toadstool leather to make a 'cave' for itself. It was quite destructive!

I got sick of manually pulling out corals to remove the pods. Since adding six-line wrasse, the problem has effectively been eliminated. The toadstool is growing like mad and the paly is healthy again. So far the wrasse is a very good citizen, and even plucks parasites from other fish to my surprise.

I took a pic of the pod if you are interested... I can dig it up and post. It was a large amphipod with rather large hook-like claws.

Hmm good thought, but between my springer's dottyback and my canary wrasse I'm pretty sure I don't have any pods left in my 50g tank, haha! However, if you could post a pic that would be excellent.

 

[hanser]

Sounds like my tank. I can grow Xenia, Kenya trees, Palys, acros and Monti caps but my zoas just hang on or slowly melt away

 

[Bill Nye]

Dont think this was mentioned, but zoanthids tend to like higher Mag and kH. I would at least try raising your mag to 1350 ish and see if that helps.