Zoas closing, shrinking, and disappearing

FishyReef

Broke Reefer!
So it seems like the only unhappy things in my tank are my zoas. I started with around 11 frags that had at least 5 polyps each. I would say about half of those frags seem to be doing okay, but the other half aren't. The latest causualties are apparently death maul zoas, which I'm really bummed about. I started with 4 polyps on that frag, lost the first two (they slowly closed, shrank, and then disappeared), but the remaining two seemed to be doing well, and I even saw the beginnings of a new polyp. But when I came in to the office after being away for the weekend, the two remaining polyps have closed and shrunk, and I can barely even see the baby anymore. The only think that has changed in my tank is that the sump is now running, and the overflow box is right above where I glued the death maul zoas - not sure how much this changed the flow in that area (there's probably 4 1/2 inches between the frag and the overflow box). Lighting hasn't changed at all. It is so sad to come in every day and see fewer and fewer zoas or completely empty frags (2 more totally empty frags today). Is there anything I can do to reverse this?
 
Zoas are one of the easier corals to keep, and also one that can melt and die off for no apparent reason sometimes.

What is your lighting, and where is the placement in the tank on these? It sounds as though you have them at the top. If that is the case, you may want to move them down closer to the sand bed. Most zoas prefer to be lower in the tank, lower flow, and obviously medium to lower lighting provided you have sufficient light to begin with.
 
Have you noticed any pests on or near them? Little black/white snails? Spider looking things? Slugs/nudibranchs? There are quite a few pests that feed on zoas specifically and would only be hurting zoas in the tank.
 
Fast, thank you for the info! I had placed my zoas anywhere from close the bottom of the tank to about mid-way up, but the one's I've lost recently have been a more brightly lit part of the tank half-way up, so they may be getting too much light. I have AI Sol lights and am still working on getting the settings right (as of now, there is never a time during the day when the combined strength is over 60%, but that might still be too much light in some areas. I managed to break off the darth maul frag and placed it much closer to the bottom in a lower flow area, and also an area that doesn't get too much attention from my urchins, so hopefully the frag will stay put there for a while and recover. I'd really hate to lose it since they are so expensive (and I made out getting 4 polyps for $10) - fingers crossed the remaining polyp opens again and grows. I think the second polyp that was still on that frag is a gonner, but the tissue is still there so there is hope.

Biff, the only critter I've seen in that area is the one that I posted about yesterday - the bug with legs that moved a bit like a mantis. I'll really keep my eyes open to see if I see any others. I did inspect the frag before moving it to the bottom of the tank a few minutes ago.

The fact that zoas are one of the easier beginner corals is what has me so stumped - virtually all of my other corals are thriving (I admittedly have a favia that isn't looking so hot, but my other LPS and the few SPS I have look amazing).
 
Yeah, I think I melted them with my light :( so no sense dipping then. I'm just going to really hope that I moved them in time. Anything else I can do other than moving them to save them?
 
I'd keep them on the bottom of the tank for a while, just to let them acclimate to your lighting. If you pull them out, inspect them real well for zoa pox, and of nudibranch/eggs.
 
Fast, thank you for the info! I had placed my zoas anywhere from close the bottom of the tank to about mid-way up, but the one's I've lost recently have been a more brightly lit part of the tank half-way up, so they may be getting too much light. I....

1+ This may be the cause. I put my first zoas ever right under my 150 watt Mh and they melted. I placed my other zoas lower or half-way down in my 29G and they are doing fine over a year later and they are growing and spreading.

Also, its not well known that there are high-light and low-light zoas.
 
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1+ This may be the cause. I put my first zoas ever right under my 150 watt Mh and they melted. I placed my other zoas lower or half-way down in my 29G and they are doing fine over a year later and they are growing and spreading.

Also, its not well known that there are high-light and low-light zoas.

Exactly!!

As a general rule of thumb.The brighter the Zoa's color,the more light they need.
 
Exactly!!

As a general rule of thumb.The brighter the Zoa's color,the more light they need.

yeah I found this out the hard way but it also helped me find out that I had a nudiebrance issue.

In which you recommended dipping in coral rx and placing lower in the tank month later half the zoa frag was saved.:Cheers:
 
Thanks everyone. Unfortunately they are looking worse despite moving them. I got them about a month ago and light acclimated them for a week on the bottom of my tank. The first two polyps began melting while they were on the bottom of the tank. I moved the frag about halfway up after a week and the remaining two polyps seemed to be thriving, and I was even seeing the start of a new polyp. Then last week I got my sump running and moved the overflow box just enough that the spot they were in started getting more light. The remaining two polyps then melted a few days after that. Since putting them back on the bottom of the tank, they've only shrunk further. I think I'm battling a too much / too little light issue with them and really think they are gonners at this point. I'm glad I only paid $10 for the frag, but it is a bummer - I had hoped to grow them out and be able to sell frags of them in the future since these things go for $75 a polyp. I'm going to go back to the same shop I got them at this weekend and see if they have any more. These were pretty bright colored ones, so the bottom of my tank is probably too dim for them at this point. I might try moving the frag again, but really not sure where to put it right now. Ideas?

Also, thank you for the info about the low and high light zoas - this is helpful and I will try to stick with the rule that the brighter they are the more light they need, without hopefully frying any more!
 
Exactly!!

As a general rule of thumb.The brighter the Zoa's color,the more light they need.

Interesting. I seem to recall the dark blue zoas need lower light.

Also, some people have seen Zoas attacked by bacteria and used anti-bacterial meds like Furan-2 with some success. Google Zoa pox.
 
Okay, so I moved it to a slightly brigher spot, still on the bottom of the tank and have now noticed what look like amphipods all over it. I pulled it out and dipped it in coral rx for 15-20m, and definitely got a few of them off, but more were right back on it within 10m of putting it back in my tank. I hate to keep moving the poor thing so much, but should I dip it again, or is it more likely that the pods are just in the rocks and will find it again as soon as I add it back to the tank? Stragely enough this seems to be the only frag they are on.
 
Interesting. I seem to recall the dark blue zoas need lower light.
As with any rule in reefing,there are exceptions.

Okay, so I moved it to a slightly brigher spot, still on the bottom of the tank and have now noticed what look like amphipods all over it. I pulled it out and dipped it in coral rx for 15-20m, and definitely got a few of them off, but more were right back on it within 10m of putting it back in my tank. I hate to keep moving the poor thing so much, but should I dip it again, or is it more likely that the pods are just in the rocks and will find it again as soon as I add it back to the tank? Stragely enough this seems to be the only frag they are on.

The amphipods are probably eating something either on or coming off the zoas.
Give them 24 hours between dips.
 
Found this guy munching on the very small remaining polyp today - I think its an amphipod but not sure. There were probably 4 other smaller ones crawling on the frag too. I don't know if they are eating away dead flesh or eating the remaining live flesh and killing it. If they are coral killers I hope they don't move on to my other zoas. I'm thinking I need to get a few fish in the tank that will decimate this pod population.

 
I had a very similar issue... amphopods (some kinds) actually do eat zoas... this happens when:
1. there is no natural predators for the pods
2. the pod population is really high
3. there is not enough food for the pods other than corals

hence, they start to go ahead and much on the zoa. But, if they are not actually eating the zoa, then them constantly climbing on them irritates them to the point that they stay closed and dont get the necessary lighting to stay alive...

solution that I did was get a yellow corris wrasse which munched up the huge pod population to the point that they did not eat up or bother the zoa's, within days I saw that my frags stayed open longer, looked healthier and started growing back. I had one small colony eaten down from about 15 polyps to only a half of one... now its back to 4 .

If you dont have any pod eating fish, if you have the room for it, its worth a try.

Hope this helps
 
Ilyad, I think you are exactly right, and am glad I am not the only one that has had this experience. A quick google search revealed that there are other people out there who have had the same problem with amphipods attacking zoas. I think this particular frag is a goner, but I really don't want them to kill the other zoas I have in the tank so am going to have to add something that will control them. I have a red velvet fairy wrasse on my stocking list - do you think it will eat them? I'm also planning to add two b/w clowns this weekend but don't know if they eat amphipods or not. Not really sure I can add two wrasses to my 90g without them fighting, and also love my two cleaner shrimp and don't want them to become food for a wrasse. Are there any other fish out there that will eat amphipods?
 
That's not an amphipod.It's an isopod.

That's far worse of a problem to have! What can I add to my tank that will eat them but not kill my cleaner shrimp? Live Aquaria says that a black cap basslet eats them but that they are deep-water dwellers so I am thinking my AI Sols will be too bright for them. Any other ideas?
 
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