Help me with my dying zoas?

tkh

New member
So, just to start the thread... My zoa colonies have slowly been disappearing, one head at a time... Like, one night it's there, the next it's gone! :( Just a stump is left in the morning.

I'm blaming some type of pod, just as I see them on the zoas, forcing them to close, and I believe they gnaw at the base of the zoa head. I know that pods are generally opportunistic, and would only be eating dead / dying zoas generally, but I swear these are healthy, happy colonies - fully extended and open, nice colors / lashes...

Naturally, for full diagnostics, I'll get my water parameters in later tonight, and I'll try to snag a picture. They likely are not isopods, but I honestly can't tell what type of pod is what, and I have a ton of pods (no fish to eat them!)

I realize it could also be asterinas (mini starfish), as I have seen one before, and found one in my sump, but I don't see why that would also cause pods to mass around otherwise healthy looking zoas?

In any case, my current plan is to hopefully get a nice friendly wrasse in soon to hunt the pods... But given my current quarantine tank setup, and delay, I am afraid that it will be two more months before I finally get a fish :( ((my last attempt at quarantining fish failed quite miserably, to my horror and shame, the poor fish! So now I am trying to be extra cautious I ensuring the q-tank is fully cycled. - even though I was sure the last time it was, I'm now just being very very careful with it all))
 
cirolanid isopods (i hope not)
Also, check with a flashlight at night for nudibranchs and maybe sundial snails. They are really sneaky. I had the same thing happen where I thought it was the pods causing the problem, but then I found a big fat sundial and realized the pods were just doing their job. Once I got the snail out everything went back to happy. It's probably also possible that you have a contaminate that is weakening the zoas to a point where the pods can eat them (might want to drop some carbon just in case if you aren't already running it). Do you have any other corals in the tank, and how are they doing if you do?
 
Thanks for the help guys! I do run carbon constantly, and recently changed it, so hopefully, if there is anything in the water, it is helping out.

They do look like the geigers, and I was really hoping it wouldn't be them! I do like them - and they are so established it would be impossible to get them out at this point, lol. At least, I think they are the geigers, I will snap a quick photo later.

As for sundial snails, and nudis - honestly, I have no idea what signs to look for, short of catching one in the act. That's actually why I thought it was the pods at first, since I've seen them go up to a healthy zoa, and rest on them, causing it to close, and then hang out, assumably eating. They are quite bold, not even running from light, like they often do - so I've assumed my pod population has just gotten too large, and they have realized they are safe in my tank. I was also guessing that they would only eat truly dead/damaged ones, so was surprised to see that - unless the zoas superficially look healthy, but truly are not.

Oh, and all of my other coral looks great actually (apart from an sps that had decided a while back to simply not extend its polyps anymore, but continues to grow). Oh, and my plate coral looks a lot happier now that it is "free" - so thank you for the advice on removing the base/plug Nate!
 
I do dose VC, and am a believer in it! :) It turned a truly ugly colony into a less ugly colony by bringing out its blue undertones, and helped my other colonies coloration improved noticeably too! I have cut back a bit however, as I'm wrestling with my sps tips turning white. I am unsure whether it was VC or just lighting, so now I have stabilized my lighting output (instead of slowly upping it over time), and once the two affected colonies don't exhibit white tips, I'll try upping the VC dose again - for now its just 1/4 teaspoon twice daily instead of the two I had been doing. (90g tank, ~30g sump but unsure the actual water volume once accounting for rock work and sand, I believe it's probably between 100 - 110g). Overall my water levels have been stable, and I've kept kH around 7.6, but I admit I haven't checked it in the last week, as my weekly water changes have been keeping the levels steadily in the "safe" zone for some time. I know, I shouldn't assume... Hence I'll post my actual levels later tonight.
 
I'd say dip in revive or coral rx ans check the polyp for anything attached to it.. And qt the coral for a couple days.
 
whats v.c.???


ok check for thoes little starfish,,i think they are called aetrea stars or something they also eat zoas
 
Asterinas do eat zoas, so I suppose it could be them - just wonder why that would cause my pods to attack healthy looking colonies too.

VC is vitamin C by the way, a great carbon dosing source with more benefits than just carbon dosing, at least according to several that do it (myself included).

I suppose I should pull them and dip / quarantine, but I am currently trying to force my Q-tank to cycle, or testing to see how it handles ammonia (threw in some dead silversides to watch the rise, or lack of a rise in ammonia. I figure this will either kick start another cycle, or demonstrate that my biofilter can handle decently large sources of ammonia, and so is ready for a fish).

Regarding coral QT... I don't have high output lights for my quarantine tank, just a simple led reading clip-on light.... It definitely won't be enough light to sustain much of anything, especially trying to get through the makeshift lid I made for the tank to prevent salt spray everywhere... So, do I have to go out and buy reef-capable lighting for my QT? It also has laminar flow - just a single koralia and a couple hob filters. I mean, I put it together for fish, not for coral originally :)
 
picture of a dying zoa colony might help us identify what might be the thing

here are the list of things to check when it comes to zoas
1. nudis .. these hide and camouflage turning into zoa color and making it very hard to identify. once everyhting is dark flash a torch or iphone flash and see if you see any thing moving on zoas
2. snails .. like Nate mentioned some snails eat zoas
3. non reef safe fish .. if you have any angels or such kinda fish ..they look innocent when you watch them but nip at corals when no ones watching.
4. asterina stars .. see closely and see if any polyps is completely covered by a star.
5. too much light they melt slowly.
6. additives some additives burn corals cause of alk swings and stuff
7. zoa pox, see if there ae any pimple like white spots on zoas

ill add if i remember something

pods may rest on corals causing them to close but i dont think they eat healthy corals


i have heard this too many times but consider this a myth " when zoa colonies reach certain age they start to die off"
 
i might look stupid but will ask anyway .

does a coral qt tank needs to be cycled ?? i mean corals arent really that big of a bioload right ?? unless we feed them plenty ..

so all you need is egg crate a tank and hob filter and a suitable light if you do wish to qt zoas . (and i think one koralia is fine if you are qting only zoas they dont need high flow)
 
Thanks tin! Umm, I'll try and get some pictures tonight when I get home. I'd be really torn if I had nudis.... I think I'd keep the nudis, lol. Sadly, my tank is fishless too - one more week! Well, and then I could add fish, which would have been perfect if my first QT tank had worked properly.... RIP some innocent fish. :(

Which leads to why I am doubling down in cycling this tank - I've been preparing my QT for more fish. This time with an appropriately large hob filter ( my first attempt failed not due to lack of a cycled tank, but simply an inefficient, and overly small hob filter).

So, ultimately, I am looking at either snails, asterinas (haven't seen one in my DT in months, but I imagine there are still a few in there, found one in my sump 2 weeks ago), or nudis as predators? I haven't seen any of the above bothering colonies, well more precisely, haven't seen any of the above period. I'll peak around a lot tonight in case I get lucky and find the culprit.

I don't dose anything other vitamin c, which is added diluted in tank water directly to the sump. As for lighting, I suppose they could be unhappy, but when a zoa melts, does a whole head literally disappear over night, leaving a stump? Most of my zoas are near/ on the sand bed, and the only one that is up high is doing fantastic, with no signs of predation (my grow-out frag!).

Perhaps zoa pox, I'll look over them. That hadn't occurred to me... Hmm, I think we need pictures to help this out! And ultimately, I am concerned in the sense that they are living creatures, but truly these are not the most beautiful or rare zoas...... I think people will laugh when they see what I am trying to save, lol.
 
Thanks Jeni! Good visual aid, very helpful for me! I definitely have that amphipod, large ones at that (Herbie's Geigers :)), and I have seen them irritating the zoas, and I swear they were eating something, as they normally are rather averse to hanging out like they were - I use a turkey baster to try and push them off / scare them into running away, but they just clung to the zoa. Maybe they were eating something the zoa was emitting due to being stressed? Still curious what I can do about this all - I'll get some pictures up tonight...
 
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