Zoanthids Wasting Away

FishForums.net Pet of the Month
🐶 POTM Poll is Open! 🦎 Click here to Vote! 🐰

sothoth

Fish Fanatic
Joined
Jul 21, 2006
Messages
89
Reaction score
0
I've had problems with keeping zoanthids for some time now. Every time I think I've solved it, I get a tiny frag to test if it's fixed, and they die too.

I did have a zoanthid predator for a little while (a snail), but now it's something different. They start wasting away and eventially fall off the rock and/or disappear.

I have a few fish, but none are destructive (6-line, lemon goby, algae blenny, firefish), and many other corals that are doing great, including daisy corals, frogspawn, star polyps, pagoda coral, fanworms, and anthelia.

I've read some horror stories about bacterial infections that cause zoanthids to "waste away." Anyone have any other suggestions? I have been checking nitrates (undetectible), phosphates (undetectible), pH (8.2), temp 76F, salinity is perfect (I test with two different hydrometers because I once had one that was reading incorrectly so my salinity was way off). I have a ton of life rock and VHO's that put out about 4wpg.

Everything is OK except for the poor zoas. they're my favorite coral, I would really appreciate any info or guesses.

It's not pox, they don't develop any spots on them, just start looking emaciated, shrivel up, and disappear. It takes a month to lose a whole colony.

Again, suggestions are appreciated! Thanks in advance.
 
Raise the temp to maybe 82, obviously not in one go but little by little, 82 is a much better temp for tropical reef tanks.
 
Hi Sothoth,

What lighting do you have on your aquarium and how deep is it? Sometimes Zoa's can develop problems through intense MH lighting in shallow water. If you have MH lighting, try placing your Zoa's in a more shaded area of the tank.

Are you using any trace element supplements? I'm just wondering if other corals are somehow out competing the Zoa's for iodine etc?

Are you feeding them with zooplankton or meaty foods that are placed on the polyps?

Are they positioned with good water movement? Zoa's enjoy chaotic water movement, not being blasted from one direction.

Are you using any filter media like phosban that contain aluminum? I have read that the aluminum can cause problems.

I agree with raising the temperature up in the tank as corals thrive in the warmer waters.

Hopefully the above might shed some light on your Zoa's problem. :good:
 
oh, and if you dont dose, how often do you change the water?
 
I have 4wgp (VHO lights in a 24" deep tank). I do water changes (10%) weekly and add small amounts of trace elements (iodine, stront/molyb, calcium). Other corals are GREAT. Whatever this is, it appears to bother just the zoas.

I'll try the higher temp.

Anyone heard of the bacterial issues reported to infect zoas? Like I said, we have a second tank with tons of zoas thriving, with a pretty similar setup as the one I'm starting to have difficulty with (same temp, same lighting wpg and tank depth, same water/salt source, same salinity, etc) . I just don't get it.

I was sort of hoping it was an infection, at least if you know what you have, that's a step towards fixing it.
 
Have you checked for spiders a couple of hours after lights out.

They are not very big so you have to look carefully.

Regards Gaz
 
Do you run a UV sterilizer or use Ozone on either tank? If it is some kind of a bacterial infection, then this would help significantly. Personally though I would look at what is differnent on this and your other tank and see if you can come up with anything. Zoa's are as tough as old boots so it is strange that this is happening to them.
 
Do you run a UV sterilizer or use Ozone on either tank? If it is some kind of a bacterial infection, then this would help significantly. Personally though I would look at what is differnent on this and your other tank and see if you can come up with anything. Zoa's are as tough as old boots so it is strange that this is happening to them.

Yeah, they're tough, which is why I'm so disturbed by it, and also wonder what the heck could be the issue. Like I said, I have a lot of really healthy corals in the tank so I feel perplexed why it's just the zoas.

I have looked for spiders in the past and haven't seen anything that makes me think there is a predator anymore. I DID have a predator some time ago, it was a snail that would kill off a whole colony in a few days. Now that the snail is gone, they last a few months, but don't do as well.

In the meantime, I'm probably going to move them to our other tank (where zoas thrive) however I'd appreciate any suggestions for a dip to make sure that if there is a bacteria or something, I don't transfer it. I have a tech-d solution which I will use prior to a transfer.

Zoas are my single favorite coral, this is very frustrating.
 
if your doing 10% weekly changes, i would really NOT recommend you to dose, thats how my tank crashed, i dosed calcium and stuff even with 20% weekly changes, crashed my tank.
 
What kind of smail? Was it a sundial snail? I recently disovered them in my own reef after a year of wondering why small zoanthids would wither away and die in the manner you're describing. The little things can and do hide during the day underneath your rockwork and wreak havoc overnight especially on the smaller zoas/zoos. You could try something like Giant Palythoa though to see if it's a small predatory snail. Giant palys seem impervious to the snails and flourish in my reef despite their presence.
 
What kind of smail? Was it a sundial snail? ... You could try something like Giant Palythoa though to see if it's a small predatory snail. Giant palys seem impervious to the snails and flourish in my reef despite their presence.

Funny you should mention the Palys, I just got some a few days ago to see if it was specific to Zoa or if Paly's would have the same issue. Too soon to tell...

The snail was not a sundial. I did do an ID but forget the name... let me look a bit...

Ok, it was most likely a Coralliophila species. There are a few types of these out there, and some that look similar (but aren't) but they are still coral predators. Mine looked very much like the ones you can see easily on the internet by searching in google images for coralliophila. It also killed off part of my frogspawn, which is why I decided it was the pest and got rid of it. I actually saw it sucking on the base of the frogspan tissue with it's snail tube.
 
For anyone who is interested, I think I've gotten this pinned down and would like to share it with you all.

It all traces back to my going on a trip to Alaska for 2 weeks. During that time, I gave explicit instructions to a guy who was watching the tank for me. He adjusted salt content, accounted for evaporation, did 1 water change, and did it all fantastically. However when I returned, I saw that my skimmer was not producing nearly as much flow or air as it should. This is a tough thing to teach a person who doesn't know much about keeping fish, since phrases like "make sure there is plenty of air and water flow" is of course subjective.

This was what triggered the whole thing.

To make matters worse, I had previously had a destructive crab in my main tank so I netted him out and plop'd him in my 'fuge so he wouldn't mess with my corals anymore. Little did I know he'd wreck havoc in there too, by picking off and/or eating all of my calerpa, so I lost most of my dentrification capacity in the 'fuge.

When I was back from vacation, I did maintenance on all of my pumps and my skimmer and got rid of the crab. All of the pumps were a little backed up, hence the problem with the skimmer not skimming. There was also excess debris in the tank, presumably due to the lack of skimming. Much of the waste accumulated in my skimmer chamber where there is biological filter media, and that was also slowing things down... the waste was excessive enough that the mechanical filtering wasn't working adequately. I temporarily pulled out the biological/mechanical filter media so the water would flow again to my skimmer.

My biggest mistakes were: 1) not putting the media back in right away, and 2) not replacing the calerpa quickly.

It all added up to this... zoanthids started wasting away. I didn't know why, but transferred some to another tank I had (that didn't have issues) and they came back to life (slowly but surely). I assumed it was a lighting problem or something. Then my algae blenny died, which was very sad.

Then hair algae and red slime started going mad and began to overgrow my corals. I used a gram negative antibiotic on the red slime, which worked like a charm, but the green hair kept going. I replaced the calerpa in the 'fuge in hopes that the hair algae would be out-competed by the calerpa, but the calerpa struggled to grow, meanwhile the hair algae was even more rampant. I tried nitrate absorbers, phosphate absorbers, etc, in hopes of curbing the hair algae growth, but nothing seemed to help. I'd scrape it off the glass, in a week it was twice as bad as before I'd scraped it off. I tested phosphates, ammonia, nitrates, etc, and everything came back spot on. What was going on?

I'm still not 100% sure, but I'm fairly certain of this... removing the biological media caused the ammonia and nitrates to blossom. The calerpa wasn't abundant enough to help much, and the waste load was just too great for my skimmer/live rock. The false negative in the nitrate/ammonia tests was probably due to the hair algae absorbing it all, which is why it was growing like crazy. I'd indeed created a great self-sustaining ecosystem, one where there was excessive waste and unwanted pest algae growing like made to use it all up. Great, huh?

My snails started dropping off one by one, and so I decided to move all of my fish and corals to a good tank (and increase skimming and filtration on the good tank) and then I moved all of my algae covered live rock to a holding tank with good water circulation, modest filtration, and LOW LIGHT. The hair algae has quickly subsided and I'll put the rock back in my main tank soon, little by little.

I've replaced all of my biological filtration media and temporarily put on a hang-on-the-back mechanical sponge filter (with a biowheel) and also added some nitrate and phos removing media (for what that's worth). So far, the algae isn't coming back, and the fish and corals are very happy in their temporary new home.

What a disaster. Luckily I only lost one fish and part of a colony of zoanthids. This could have been much worse. But the stress was bad, I really hate losing corals, I have too much respect for the ocean inhabitants to take this lightly.

When I replenish this tank, I'm also going to stock it more sparsely, just in case, and get a better skimmer. I usually argue with people who drop $300 on a skimmer for a 25gal tank, but not anymore. :) Also, I'll never underestimate the destructive power of crabs, the importance of healthy dentrifiers in a 'fuge, or the need to think a little beyone the results of water test kits.

Anyway, thanks to you all for your suggestions along the way, and let this be a lesson to everyone and be smarter than I was, and don't assume anything when water test results come back looking good, that doesn't mean everything is as it should be.
 

Most reactions

trending

Staff online

Members online

Back
Top