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FAQs about Zoanthid Environmental Disease  (Pollution/Poisoning, Lighting...)

FAQs on Zoanthid Disease: Zoanthid Health, Pests, Predator 1, Zoanthid Health, Pests Predators 2, Zoanthid Health, Pests, Predators 3, Zoanthid Hlth., Pests, Pred.s 4, Zoanthid Hlth., Pests, Pred.s 5, Zoanthid Hlth., Pests, Pred.s 6, Zoanthid Hlth., Pests, Pred.s 7,
FAQs on Zoanthid Disease by Category: DiagnosisNutritional, Social (Allelopathy), Trauma, Pathogenic (Infectious, Parasitic, Viral) Predatory/Pest, Treatments 
& Zoanthid Reproduction/Propagation,

Related Articles: Zoanthids, Sea Mat: An Ocean Of Color For The Aquarium by Blane Perun,

Related FAQs: Zoanthids, Zoanthids 2Zoanthids 3Zoanthid ID, Zoanthid Behavior, Zoanthid Compatibility, Zoanthid Selection, Zoanthid System, Zoanthid Lighting, Zoanthid Feeding, Zoanthid Reproduction

Like all photosynthetic life, Zoanthids need measurable (not zero) NO3 and HPO4

Dark Red Encrusting Algae Killing Zoas... BGA       4/4/14
I have what I thought was dark red coralline growing in a lot of the rock in my tank.
<Mmm; likely BGA>
All colors of coralline seem to expand rapidly in my tank, so didn't think anything of this color.
<Does it feel slimy?>
However, over the last few days I've noticed that it's grown onto a few Zoa colonies and now they are not opening, so I'm a bit worried. It's the exact color of Cyano, but seems to be encrusting just like a coralline. It feels slightly slick to touch and is fairly difficult to scrape off, though with a fingernail I can scrape a bit unlike purple coralline which won't budge. It appears to be growing mostly in high light, high flow parts of my tank. Any ideas what this might be and how to combat it?
<As we've both stated>
tried a few days of lights out like I would with a Cyano outbreak, but no apparent effect. May try a peroxide dip or even Red Slime Remove next (though have had bad luck with it once before so hate to even consider it). Any advice is appreciated.
<Time to send you; have you read re Cyanobacteria and their control on WWM.
You know how to search, use the indices?
Bob Fenner>

re: Dark Red Encrusting Algae Killing Zoas       4/5/14
Appreciate the quick reply. I had discounted Cyano because this is so resistant to high flow and manual removal.
<Mmm; not all; by a long-shot>

I literally have to scrape it to remove it from rocks and it's growing in the highest flow areas of my tank. Are there growth forms/species that
don't follow the normal characteristics?
<See WWM or my Algae Control book (on Amazon) re. BobF>

Rotting Zoas... BGA, env. 3/31/11
I am having a problem with one of my Zoa colonies. Over the weekend a red algae (it almost looking like red spikes)
<Likely BGA... and the conditions that allow/ed it. Prominent in your photo.>
started growing on one of my Zoa colonies.
Over the next few days the polyps began to close and the red algae began to grow. As the algae spread polyps began to rot and flake off. Today I fragged what was left of the "healthy" colony and it seems to be fine for now. I really don't know what this is. My Parameters seem to be fine Ammonia 0 Nitrites 0 Nitrates 10 Alkalinity 9dkh Calcium 400. I am running a protein skimmer as well as Chaeto. I use R/O water with a 0 TDS rating. No new additions or change to equipment. The red (spikes) in the picture are towards the front of the rock as well as growing on the back.
Anything you could tell me would be much appreciated
<Your water quality is "the reason" here... But do start by reading:
You need to fix the environment to not suit the Cyanobacteria. Bob Fenner>

All my Zoanthids are closed! 2/28/10
Having searched all through WWM and other forums for help with my problem, I have had no success. All of the Zoanthids in my system are closed, and the have been for over 3 months.
<Summat's up>

I have done a hydrogen peroxide dip and a freshwater dip on all of them (I have about 6 different kinds...) over about the past month or so and there is still no change. The hydrogen peroxide dip did seem to get rid of some fungus
on some of them, but the freshwater dip cleaned off nothing but a few small pods and some snails (not sundial though). I have looked at all times of the day and night and have yet to find one Zoanthid spider, sundial snail, or Nudibranch on any one of my colonies. Also, the Zoanthids are not 'melting away', and some of them still look very plump.
My system is very small, 10g with a 5g refugium of Chaeto. I know there might be a problem with allelopathy among the Zoanthids,
<Ah yes... likely in/with such a small volume especially>
but wouldn't one of the colonies be thriving while the others are closed off?
<Mmm, nope. All could be, are apparently "losing">
Also, there is only a crocea clam, and two small xenia and clove polyp frags <Either one of these could be "winners">
in there with them, each of which is thriving. There is only one fish in there right now, a yellow watchman,
<Needs more room than this>
and some Turbos and Astreas. The only other thing I can think of is that my lights may be old, I am running a 70w MH unit about 8 inches above the water and the bulb is about 8 months old... it is a good bulb though and like I said this has been going on for months so I doubt this is it. My water parameters are good, too:
SG 1.024
<S/b higher. See WWM>
Ammonia 0
Nitrite 0
Nitrate 0
<An essential nutrient. Could be the trouble here>
Phosphate 0
<Ditto. Remove, reduce your chemical filtration, increase feeding>

Ca 1350
<Mmm, no>
dKH 9-10
Mg 1525 (I know a bit high... but I doubt this would do it?)
<Yes, could>
Temp: 78-81
Lighting: 70W MH for 7hrs, actinic 2x18W 9 hrs
Flow: 2 90gph pumps, 1 Koralia Nano
I also have My tank has been up and running for over two years now and I have been able to keep Zoanthids fine until about 3-4 months ago. Attached are some photos of my closed colonies. I am at my wits end and ready to throw my tank out. I know Zoanthids can be finicky, but I would think at least one or two colonies should open. Any ideas?
<... fix your water quality first, do what is necessary to provide some NO3, HPO4... Move the colonies elsewhere... Bob Fenner>

Re: All my Zoanthids are closed! 2/28/10
Thanks for the quick reply. I think I will move the bigger colonies to the LFS and be content with Xenia/clove polyp/clam...
leave one or two small Zoa frags, and try to get the water quality right.
The problem with Nitrate and Phosphate is that even when I feed a lot they are still undetectable, I assume due to my Chaeto in my "refugium" which grows quickly.
<I would keep harvesting this Green Algae; to the extent where there is some measurable essential nutrients here>
However they must be in there somewhat because I still have significant green hair algae.
<Oh! Then address this first. See WWM...>
Could it be a problem with ph/alkalinity swings?
I add Kent Superbuffer regularly
<S/b only done through additions to pre-mixed, stored new water during change-outs>
but there could still be swings and this I have heard to affect Zoanthids. Or are you pretty sure it is allelopathy?
<Can't discern from here>
I am pretty resigned to the fact that this is it. Again thanks a lot for the service.
<Certainly welcome. BobF>

Zoanthid and mushroom failure in nano tank 11/25/08 Please Help!!! I have a 24g nano tank that has been running since May 08. Several large pieces of cured live rock with 2" sand bed. I added 1 small powerhead for additional water movement. I ordered a small nano polyp/mushroom pack from DrFoster&Smith online after my tank thoroughly cycled. polyps and mushrooms were doing very well for about 3 months, opening expanding etc, then one day they started staying consistently closed and started dying. Water Parameters. I have tested, double tested, triple tested, had LFS test and all my water parameters and all are pretty much spot on. Water changes done weekly of 5g using Instant Ocean Reef Crystals aerated for 24 hrs before adding to tank. Lights are on for about 12 hours. Lights are new with aquarium bought in May, but as a safety measure bought new lamps a month ago. Add B-Ionic and Iodine. Again double, triple checked I was dosing correctly. Livestock (Nitrates 0) 1 percula clown 2inches 1 blue damsel 1 inch 1 blood red shrimp 1 bi-color Pseudochromis 2 inches 6 red legged hermit crabs and 2 turbo snails as a cleanup crew Here is the catch, I also have a 90 gallon FOWLR tank that I'm converting to a reef tank. Once I got the fish sold to LFS and the Nitrates down I started adding polyps/mushrooms. The water parameters of my 90g match that of my 24g...but my nano is failing. So as a drastic measure I took polyp/mushroom frags from my 24g and placed in my 90g and they are doing just fine and in fact opened within a day!!! I'm at a complete loss of what the problem is with 24g tank. My only theory My 24g tank is at my office. The building is pretty old and I'm using tap water to mix my salt. Is it possible that copper or some other metal/crud from the old pipes could be affecting the outcome of my 24g nano? My 90 gallon resides at my condo that is actually a brand new hi-rise in downtown Chicago...all new pipes etc. One other small issue, I seem to have a little extra algae growth in my 24g nano than my 90g....phosphates of both sources are 0. I just attribute the extra bright green algae growth to a shallower tank with good lighting. Oh, and one last thing, there was a 8-9 hour power outage around the same time that these polyps/mushrooms in the 24g stop opening. I just figured several months later should be more than enough time if they were shocked to re-open....but it took moving them to my 90g to get them to open again. Well hopefully this is enough info...if you need specific numbers on my water parameters I can email a pdf of a ongoing chart I keep of all water parameters. <Obviously, there may be something going on with your nano although the setup of your nano sounds good. I would cut back the time the lights are on to 8-10 hours. That's probably the reason for the algae growth. You mentioned you are using city water. Are you putting in any water conditioner to remove chlorine and chloramines? Secondly, you mentioned the possibility of copper in your water coming from the olds pipes in your office. I would highly suggest you getting an RO/DI unit to eliminate any possibility of this. You can use it for your home and office tanks, the best way to solve water quality issues are to start with good clean water. Of course you saved the best for last, a power outage!!! These are terrible events for an aquarium. Your polyps could have been shocked from the lack of circulation when this outage occurred, its a normal sign of stress and usually they will be back to normal within a few days. How long was it before you transferred your corals from the 24 to the 90? What kind of test kits are you using? Have placed anything in the 24 since? Also remember that as live animals, corals go through stages just like every other living creature, there are going to be times when they just don't feel like opening. If you stay on top of your system, watch it every day, you'll get a feel for the tank and be able to recognize these stages. You'll be able to immediately tell when something is wrong and you need to take action, or if its just a normal thing that your corals are going through.> Thanks, Brian <You're welcome and good luck!!! -- BrianG>

Brown coating on Zoanthid - polyps not opening -08/13/08 Good afternoon. I have been doing a lot of research on my current problem but I can't seem to lock it down. I have some Zoanthid polyps that are no longer opening due to what I would best describe as brownish green algae growing on top of it. <This algae (which looks like Cyano- or a combination of algaes) is more a symptom than a cause. It does not grow over strong, healthy Zoanthid colonies.> However, I am unable to scrape it off of one test polyps. Someone told me it could be brown jelly, but it doesn't look like it. <Nah, not brown jelly. Brown jelly is unlikely to be found on a soft coral.> Attached is a picture of what the algae like substance is. Sorry for the quality of the pic. You can see the unknown substance growing on the closed polyps. I took a fellow reefer's advice and tried a Lugol's dip, but it did not fix the problem. <I do think this is likely a water quality problem (might also be a lack of water flow). Please see: http://www.wetwebmedia.com/watrqualmar.htm (and associated FAQs, algae control, etc.)> The unknown pest is not affecting anything but my Zoanthids. Everything else in the tank is thriving, and it is slowly spreading to this colony as well as others. Water parameters are all normal. I was wondering if I will be forced to start trimming the bad stuff out or would it hurt to try using another type of dip? <I would first increase water flow to the area, see if that helps.> Thank you,
Sara M.>

Zoa trouble…A follow-up Email Requested 3-30-08 Hello Crew <<Kyle.>> I have a problem I was hoping you could help me out with? <<I will attempt to.>> I have been in the hobby for about 4 years now. First off I have a 65 gallon aquarium with a 20 gallon sump and 250 watt medal halide. My alkalinity is 11 dKH, my Calcium is 450, 0 Ammonia my nitrates and nitrite within normal parameters. <<Sounds good thus far.>> When I started collecting coral I read that mushrooms and Zoas were very hardy corals and a good way to get started. <<A good but general direction.>> That was about 4 years ago. I have a great collection of coral that all thrives in my tank but I have NEVER been able to keep Zoas. I have tried several types, colours and sizes but still they all die. I acclimatize them for approximately two hours before placing them in my tank. I have tried Zoas from friends, LFS and random people but every time without fail I get the same result. Recently I was given some electric green Zoas. For about a month they were thriving even growing new polyps, but for the past 3 or 4 days they have not opened or at least half opened and it's the same old story. They look like they are on the way out. I am at a loss. The Zoas are near the bottom of the tank in medium flow. I have tried several different placements with all of my Zoas. I keep them in the same area for usually a month and then try another area if they are not doing well. I am currently successfully keeping blue candy cane, several different mushrooms, elegance, 2 clams, red Monti, finger leather and frog spawn. I do a 10-gallon water change every week (well sometimes week and a half depending on how lazy I am but at least every week and a half.) I'm wondering if you have any suggestions? <<Kyle usually with Zoanthids varying water quality is the culprit in regards to failure with them but that does not appear to be the case with these…By chance are they getting white spots/bumps on the oral discs? What type Kelvin is your bulb and how "direct" is the light the Zoanthids are receiving? What type of lighting are on the tanks you usually do your purchasing from? DO you does or test for iodine? Any potential predators in the tank; snails, crabs, urchins, fish (what type do you have)? All of these questions may seem remedial or unrelated but they will help to diagnose some issues as well as eliminate others. In the meantime check out the articles I linked below.>> Thank you for all your help <<http://www.wetwebmedia.com/zoanthid.htm http://www.wetwebmedia.com/ca/cav1i1/blane-zoanthids/zoanthids.htm >> Kyle <<Kyle I look forward to your response and assisting your further, Adam J.>>

Re: Zoa Trouble 4/1/08 Thank you Adam for your quick responds. <<Anytime.>> (sorry I sent one this morning but I was in such a rush I called you Kevin. My bad) <<It's okay, Adam's not my real name anyway…sort of a stage name like those gals at the adult bar near the airport.>> There are no white spots/bumps on the disks. ( I read that can be caused by overexposure to light ?) <<Affirmative.>> Some of the polyps are 1/4 open it looks like they are squinting. But a lot of the polyps are brown and look as if they are rotting. I can send a picture if it would help just let me know? <<Wouldn't hurt…send it along.>> I have 14,000 HQI Phoenix Electric bulbs and I purchase them from Reef Perfection in London, Ontario. I have placed some Zoas directly under the light. I have placed some in caves to give them less light. <<Moderate light about halfway down…to the bottom of you tank would be appropriate.>> These Zoas that I have now are the closest Zoas I have had to living and they are on a rock near the bottom corner of the tank. I do use Iodine but I just add it here and there and I have never tested it, could this lead to Zoas not opening? <<If you are dosing properly and doing regular water changes I doubt this is the problem, however you should be testing for every chemical/mineral that you add to your tank.>> As for predators I have 2 clown fish, a six line wrasse, yellow tang and a bi colored angel. Lucky none of the fish pick at the coral. The Bicolored angel and the clown fish sometimes have minor scuffles but nothing serious. I used to have several hermit crabs but I am now down to just one. He doesn't seem to bother the coral just wonders around aimlessly. I also have an emerald crab (I think but I haven't seen him in a month or two). <<I wouldn't have the funeral quite yet.>> I have done a lot of reading on Zoas in the last several months; I was reading an article about tiny predators eating the Zoas. <<Likely this little attractive but very predatory guy; http://www.reefs.org/hhfaq/snails/faq_heliacus2.jpg/variant/medium .>> Is there any way to detect this ? <<A small, preferably red, light during night time hours…moving the colony (if possible) to a controlled/quarantine environment would be a good idea as well.>> Also if the rest of the coral is opening and thriving is there anything that would only effect Zoas? <<The Heliacus snail image I posted above would fit that that description and they are nocturnal, however I doubt that just one would cause the behavior you describe in your colony during day time hours. I'm still concerned about environmental issues here as well.>> I bought a yellow Fiji leather 3 weeks ago but it melted down about a week ago. <<Now I am definitely suspecting something environmental, though the yellow Fiji leathers are much more sensitive than their hardier cousins. Is there any chance you have any metal compounds making there way into the tank?>> I have been running carbon attempting to remove any toxins left behind from the leather. <<That along with a poly filter and lots of water changes would help, and do consider the benefits of not just quarantining fish but inverts as well…and while your at consider the consequences of not doing it.>> I really hope this helped please let me know if there is any other information I can offer. <<At this point I am still making educated guesses, it's difficult to pinpoint something at the moment. The picture may not help for sure, but it will certainly not hurt…do send one along to me if you can. Zoanthus are more susceptible to disease when placed in turbid water near lots of sedimentation/substrate which can irritate the colony…imagine getting rocks in your mouth when your expecting a steak. In the meantime, take a look at this article as well; http://www.springerlink.com/content/jr2lhp1g5l257418/ ; -Good luck, Adam J.>> Re: Help with Zoas 4/1/08 Hey "Adam" <<Kyle.>> Thanks again for all the information. <<No worries.>> I love to read on any thing Salt Water and although I have already read many of the articles on WetWebMedia.Com they are very helpful. <<Yes I think this is true with many things, you don't catch it all the first read through.>> I have never seen a snail like that in my tank before so I'm assuming its not that. <<Okay.>> I sent you a picture its not the greatest but hopefully it will help. <<Thanks but unfortunately it's a little to unfocussed and distant to be of much help.>> As to your question about metal, my lights are 8 inches off the water and are being held up by rebar would this effect the tank ? <<As long as you watch them for rush and corrosion, I would think not.>> I did not think about the rebar having any effects because it was so high off the water ? Is there anyway to test for metal in the water? <<If there is any it would likely come from your source water, I would contact the local powers that be for an analysis of it….that is if you are using tap.>> The only other metal is a screw on my Mag 7 pump but that was already on the pump. Is there anything else you can think of that would be a large environmental hazard ? <<I'm not seeing anything obvious in this situation.>> I really want to know where I'm going wrong I wish I could keep Zoas. I don't know what else to tell you ? Maybe I should try a large 30%-50% water Change ? <<Perhaps, but I would still be interested for you to attempt keeping some in quarantine in control system and see if you still have the same issues.>> Anything you can offer would be much appreciated. Thank you very much <<Good luck, Adam J.>>

Disappearing Zoanthus  2/28/07 Hello. <Hi.> I just recently (about an hour ago) found your website. <Welcome.> There is SO MUCH info on there that my brain is starting to hurt from reading so much.  :) <D@mnit Jim I'm an aquarist not a Doctor...that's a little Trek humor for you.> Here's my tank specs, first: 135 gallon 40 long fuge/sump protein skimmer cascade filter with in-line heater direct to tank <Is that a type of canister filter?> titanium heater in sump third heater (glass) in tank Compact Fluorescent (orbit system), running 10 hours of actinic and 9 hours of daylight <Okay.> Specific Gravity-1.026 Ammonia, Nitrite, Nitrate, Phosphate: 0 Calcium-around 400 <Sounds good thus far.> Here's my problem: I purchased 2 different zoo frags from an individual on Jan 21.  One of the frags is about 4 inches from the bottom of the tank and the other one is about 12 inches from the bottom of the tank.  The one that is closer to the bottom is doing GREAT.  It has numerous new polyps on it.  The one that is farther from the bottom (closer to the lights), however, is not doing so well.  Polyps are actually starting to disappear.  I am wondering two things.  First, could my long spined sea urchin (who has eaten almost all of my star polyps) be eating the zoos? <Perhaps, though many times Urchins are simply destructive through their clumsiness and not always predation.> Second, should I move the zoos that aren't doing so well down so they are at approximately the same height as the ones that are doing well?   <Well if you had high powered lighting such as Halides I may be inclined to say yes but with what you have it doesn't sound like that's the issue, in their current state it would not hurt to try though. You may also have a Heliacus snail in the tank, common predator of Zoanthus.> Thank you SO MUCH for you help.   <Anytime.> LIZ <Adam J.>

Yellow Polyps  - 03/12/2006 Hi guys,<Hello Dave.>      Great site with tons of useful info.  My problem is with my golden polyps, <believe they are yellow polyps.> they have been in my tank for approx. 1 month, half of them on the same rock seem to be fading away while the others are doing fine.  They have medium water flow over them 10000K lighting and water parameters are all good.  Button polyps and other soft corals are doing great.  Should I remove what looks like dying polyps from the tank or let them be?  <I would move the colony in a different area with a little less water flow.  They really don't like medium or strong flow.  Would not remove dead ones, may cause more problems at this time.  Do Google search our site, keyword, "yellow polyps".>    Thanks,  You're welcome.  James (Salty Dog)> Dave

Dead Zoanthids - Cyanobacteria 11/5/04 Two weeks ago, I had a bad case of red slime, an F/S recommended I added Ultra Life's Red Slime Remover, so I did <Aiiiieeeee! No, please say it's not so :( This is an anti-biotic. Do look up the root definition of the term. Or, no... I'll spare you: anti-biotic: against-life Sure... it kills the Cyanobacteria... and so much more! And sadly, red slime algae is staggeringly easy to kick without hardly lifting a finger. Its all about controlling nutrients. Not allowing thawed pack juice from frozen foods into the aquarium, skimming aggressively, increasing water flow and water changes. A cure in 2 weeks or less> and it worked great. The red slime was gone but also an entire colony of zoos. The zoos closed up and are turning a dark brown should I just give on them and declare it a lost or should I just wait and see? How do you even know when a zoo is completely dead? William <water changes, good water flow and time/patience my friend. And please do read through our archives on BGA/Cyanobacteria/Red Slime Algae my friend. So much info. Anthony>

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