Zoa help
 

I picked up a mixed zoa colony when I was down at the coast a few weeks ago. I started to notice a few days ago the polyps are not expanding as much as they were when I bought them, and they seems to be somewhat dulling. I expected the dulling because the light setup they were under previously would stimulate zooxanthellea far more then my old 150W. But the polyps seem to be shrinking or shriveling somewhat which is worrying me. I checked out my water yesterday and today to see if it was cycling or anything and it seemed fine:

Ammonia: 0
NO3: 0
SG: 1.026
Temp: 26
Dkh: 7.3
Calcium: 390-400
Mg: 1350-1400

+10% water changes weekly

Right now I have only a few other corals in the tank but they seem happy, a small mushroom and 2 ricordia yuma. Before I had a acro, pavona, hydnophora, and pagoda coral that did well.

Off the top of my head the possible causes could be:
1. No fish or food is in the tank. The tank was in a fallow period and I have not yet added back any fish. There is very little food going into the system right now. A pinch or 2 twice a week.
2. Pod city. I have read they can be harassed by pods, and my tank is packed full, again due to the fallow period.
3. Cyanobacteria. I was not changing my filter socks enough, now that I have switched to changing ever 2-3 days the front glass is going back to green algae from red.
4. Foam background/spray paint. Could possibly be leaching into the water.
5. Sickness of some kind?

Any suggestion would be awesome and greatly appreciated. I am really worried though zoas and I have never done well historically. In my last setup they always seemed to dwindle away.

if you bought the frag from a fresh shipment on a piece of rock then possible predators like nudibranch.

could be pods but where my fragtank has no fish they are in there by the hundreds...large ones too and ive been watching them they seem to do no harm.its also amphipods that are the ones being watched for eating zoas...same with the asterina stars im watching mine like a hawk as they are huge i have one we found the size of a quarter:P


i would try moving the zoa frag around, if its a deepwater species they are know to melt away faster and for who knows what reasons.

Could it be a low flow or to much light? The turnover in the tank is 25x plus but its not in the higher flow area, but the polyps are moving back and forth a bit.

that would be fine in fact they can handle much more my tank is running over 50x and my zoos grow nuts even the slow growers.

phosphates is a concern,as can be too much light....generally start all zoas down low on sand move them once all polys stay open all the time.

also zoas and palys are a vast speces so if this coral doesnt make it another may flourish....zoas can lose their frill and come back and can stay closed for many weeks.....when it dies the polyps will melt fast:) good luck

do you have a pic or a web pic of the coral??

I will see what I can whip up for pictures.

adding some vitamen c may also kickstart them

They might be looking better, its hard to tell right away. The only change so far was adding some higher nitrate water from my other tank. I am thinking about fraging the piece and trying it all over the place and hopefully it will like one.

are they in ulns?? imo zoas like small amounts of nitrates, i target my tank at 10ppm:)

The tank is still fallow for over 8 weeks, plus for a 40G system 20G is Macro and Mangrove refuge. So 0 or very close to it on NO3. I only have AP kits for NO3 so I guess it could easily be 1-6 ppm and still show the color for zero?

it'd be good to see a pic for sure.
but IME (and my experience is fairly limited)
My zoas do best on the sand bed or low on the rocks, I have tried some in higher flow areas and they seemed to melt overnight, I managed to save them though. Can you visually see anything on them? I would pull the frag for a look?
Also I wouldn't right pods off, especially amphipods, I am on nano reef as well, and a couple people as of late have found amphipods to be the culprits of agitated zoas so placing them in slightly high flow has help, also dipping. but IMO that may only be a temporary fix for amphipods as I am sure they would come back eventually.

Absolutely chances are if your macro is growing there's something in there:) API is not a horrible teat for nitrate def accurate enough :)

zoas
 

Pods will pick at them, I just had the same problem with my gold zoas. Stayed up late a few tinmes and watched them eat them.

That's why I bought my copperband butterfly as they don't sleep and hunt those nasty amphipods all night. I got rid of them nearly to 99% and only see a rare amphipods here and there (very rare now).

But the real thing that helped my zoanthids is dosing with vitamine C and I have been doing this for over 6 months now.

Mine all seem to much prefer being close to the metal halide and strong flow. They need feeding as well and they seem to do well with Chromaplex, fauna marin food and Reef Energy A and B.

Some zoanthids are nearly impossible to keep (thinking blue and purple hornets) and some are nearly undestructible (like the pink and gold paly, rainbow paly, armageddon and a lot of paly).

I have theared apart those pink and gold only to seem them sprout all over the place like crazy. can't kill those, no matter what.

Oh, and they HATE water change, so I do them as little as I can. I prefer dosing instead and do water change once a month.