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FAQs about Zoanthid Behavior

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

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

Zoanthids; beh....   3/23/16
<Hi Angie, Carole here>
So my Zoanthid is looking like a teepee or nipple why ?
<A teepee or a nipple? How many Zoanthid polyps are we talking? Do you have a single polyp?>
Do I have to get it out before it affects my whole tank?
<Zoanthids close for a variety of reasons but most likely they would not affect the entirety of your tank.>

Alkalinity (SeaChem products) and Zoanthid Behavior 12/21/11
<Hello Steve>
I have a 46 bow front with a 120w LED fixture. I am currently turning over my water about 50x an hour using 4 power heads and a HOB protein skimmer. I have about a 3" LSB and 50# of LR. I have 2 clowns, 1 Green Chromis, and 1 Damsel. My coral consists of a colony of Clove Polyps, 2 Orange Yumas, a colony of Branching torch coral, a colony of Branching Hammer coral, and a small zoo colony. I also have several hermits and snails as well as 2 Peppermint shrimp. I noticed several weeks ago that my zoos were not opening. I tested my water and here were the parameters I got. Sal 1.027, PH 8.4, Alk 4.5 dKH, Cal 460, Mag 1600, temp 80.2F. I used several test kits to confirm my reading and they were accurate. I brought the Alk up to 8 dKH over a couple days using Reef Builder. Then I let the tank settle a few days and did a 20% water change which leveled out the Mag to 1280 and my salinity went back to 1.024. The problem is that I cannot keep my Alk up. It keeps dropping to about 4-5 dKH over the course of a few days.
<Is not dangerous in a well maintained system. Might want to get the calcium down to 400.>
Now my Mag is slowly increasing again.
I have not been dosing with anything except when I raised the Alk.
<Reef Builder does contain magnesium and likely the reason your Mag is going up.>
I have not noticed any precipitation. The owner of the LFS was baffled and did not believe me when I told him what my parameters were. Do you have any idea what could be causing this and what I can do to solve it?
<I would use Reef Buffer for raising the alkalinity in your particular system. Reef Buffer has a higher pH (8.6) and allows for greater pH stability in a reef system where the bioload can be significantly more than in a fish only system.>
I have looked through your website but cannot find anything that helps.
<As to the Zoanthids not opening, it is likely due to your high (50X) turnover rate, they do not appreciate high water flow.>
Thanks in advance,
<You're welcome. James (Salty Dog)>
Steven Edmiston

Purple Deaths Moving? Zoanthid beh. 11/11/11
Hello staff. I have a question that I've researched and cannot seem to find the answer to. Recently I have purchased a 3 polyp frag "Purple Deaths"
<... I take it these are these Zoanthids:
at the SCR ReefAPalooza event.
<Mmm, was there>
They have been doing great in my Nano Cube, while keeping them at the bottom of my tank in direct light. The seller had told me that this coral prefers weaker lighting and would turn a lighter brown when under strong lighting. Well about 2 weeks later I added a Harlequin shrimp to help a bit of a starfish problem. Well after about 2 nights, of the new addition, I noticed that my purple deaths had moved about 3 inches from the front of the tank to the back corner.
<? Moved? How?>
The polyps still properly faced and no sign of them rolling into place. I figured the current must have moved them there, but they seemed to "arranged" for it to be natural. I left them in the spot not moving them back because they seemed happy there, fully opened n what not. So now a few more days have passed. This morning I was doing my routine check and everything was in place, including the Purple Deaths. Well after coming home later this evening I notice the Deaths are no where to be found! I grab a light and look around to find them about 5 inches from their previous location. Even more perfectly placed upright, and in the center of the given space. Is my H. Shrimp moving them?
I never heard of them doing such a thing. And there is no way the current moved them, there is to many obstacles in the way. I have a H. Shrimp, a Peppermint shrimp, 2 Clowns, a Barnacle Blenny,
<This is the most likely mover by far>
2 turbo snails, and 2 hermit crabs
<These anomurans second>
. I don't believe any of these creatures behave this way. Any thoughts? Is it possible the shrimp knew this coral likes lower lighting and placed it in the shade? I don't know what to make of this strange occurrence.
<I'd place a bit of small rocks around the colony... IF you can find it!
Bob Fenner>

Unusual tentacles on Zoanthid colonies 5/8/10
I've been a huge fan of your site for quite some time, and appreciate the help and knowledge you share with hobbyists.
<We share!>
My question doesn't really pertain to a problem per se, just an unusual situation that nobody's been able to explain.
First, system specs:
-200 gallon mixed reef aquarium (SPS, LPS, softies, Zoanthids)
-Lighting: 2x 250w MH, 2 x 150w MH (Hamilton 14K) with 3x PowerBrite actinic supplementation
-100 gallon Rubbermaid remote sump
-Barracuda return pump
-Dart closed loop
-2x Vortech MP40W
-MSX 250 skimmer
-Carbon in ViaAqua reactor
-Korallin Ca reactor w/ all top off water going through Kalkwasser reactor
When examining the aquarium the other day, I noticed some strange, larger tentacles coming out of a Zoanthid colony. I've had this colony for over three years, and have split it several times (but not recently). I noticed that one of the other colonies (same morph), located about 12" away, is exhibiting the same behavior. The only recent change made was changing out the activated carbon the day before I noticed this.
A picture is worth a thousand words on this one, so I'm attaching a .jpg file.
<I see this, these "excited" tentacles>
Thanks for any light that you can shed!
<Something has got this colony excited/riled... likely either food stimulus, or chemical interaction w/ other Cnidarian life here... Could be a harbinger of trouble... Please read here:
and here: http://wetwebmedia.com/zoanthidcompfaqs.htm
and the linked files above these areas... till you feel you understand what is likely occurring here.
Bob Fenner>

Zoas Not Opening 4/22/10
Hello there,
<Hi Eva>
I hope you can help me out with a problem that I am not able to find any answers to.
<I'll try my best.>
Got a 100g wet/dry all in one setup (new tank with sump and skimmer is in the works). No skimmer at the moment, 4x T5's, two powerheads (not sure what size they are but on the not so powerful side), 50 lbs of live rock, two clowns, two black & white Chromis, Starry Blenny, mandarin dragonet goby, watchman, two Clown Gobies, Peppermint Shrimp, cleaner shrimp, Emerald Crab, coco worm, crabs and snails. Tank parameters are "normal" Amm. 0, Nitra. 0, Nitri. 0, Calc. 420, Alk. 10-12, SG. 1.025 pH is fluctuating between 7.8 and 8.4 within day and night and I am wondering if that is the problem.
<Is a pretty good swing but if not sudden, shouldn't be a problem. Is normal for small changes to occur during a 24 hour period.>
There are about 10 colonies of polyps in the tank, only two of them are on the larger end, most are 5 - 10 polyps. They were all doing extremely well until about 2 weeks ago.
<Mmm, did you add something to the tank two weeks ago?>
Regular water changes have been performed. There is also a Hammer Coral and a Duncan Coral which have been behaving a little odd, extending and shrinking a lot. The Sun coral, Green Star Polyp, Pulsing Xenia, Open Brain, Frogspawn, Candycanes and Acan are all doing fine.
<The Hammer and Duncan coral are not the easiest species of corals to keep. You may not have enough light and water quality may be sub par for keeping these corals. Since you didn't state tank dimensions, length, wattage, and
Kelvin temperature of the lamps, I cannot comment further with the lighting issue but the lack of a protein skimmer will reduce water quality. Another issue you may have is that Euphyllias, of which the Hammer Coral is, are high on the allelopathy list (aggressive), and may be the reason your Zoas are not opening. Care should be taken so that no coral is placed within six inches of the Hammer Coral, as their sweeper tentacles are capable of extending up to six inches and will sting corals they come in contact with.
Protein skimming is a must for reef tanks, and use chemical media is highly recommended. These two in tandem can/will reduce the effects of allelopathy in it's chemical form.
The black and white Chromis were added about a week ago but the Zoas haven't opened normally in about two weeks. I was dosing with Strontium and Calcium but not a lot, less than it asked for on the bottle but I heard that I shouldn't be dosing at all since the water changes would take care of all that.
<Not always the case, will depend on the absorption rate by the animals kept in the system. Is best to test to avoid under/over dosing. You did not state magnesium levels in your system, and it is important to maintain this element at the proper level (1250-1300ppm) as it allows corals to absorb the calcium that is available to them.>
Any information is greatly appreciated .
<You're welcome. James (Salty Dog)>.
Re Zoas Not Opening 4/22/10 - 4/23/10

Thanks for your quick response.
<You're welcome.>
So I have to come to the conclusion that the hammer and the Duncan are not affected by anything that's going on chemistry wise.
<Mmm, I didn't say that. Read the original thread again.>
I think they are being harassed by a tank occupant, have yet to figure out which one.
<Tis a possibility.>
As far as the Zoas go I have gathered the information that you were asking for in your response. I just got a Magnesium test and performed the first test (I did two) and the Magnesium is at 1170ppm. I have a feeling that that is too high.
<Not, I stated the range if you have read my last response entirely.>
It is 3 x 10000 K and 2 x 54 W.
<? OK, based on the original thread (4 T5's,) I'm going with three 10K lamps and one actinic lamp.>
There actually was something changed about two weeks ago. We took out the carbon bags (ChemiPure) that we use in the filter and it took us about two or three days to replace them. the Zoas were all doing fine before we took them out (it was time to take them out) but never went back to normal. We also use a filter pad that is sitting on top of the remaining bioballs.
<The Chemipure will help with the effects of allelopathy.>
As far as the allelopathy goes...the hammer is a few inches away from some
Zoa rocks.
<Not far enough, again, read original thread.>
Could it be a chain reaction? The first one closest to it closes up and the other ones follow?
There are actually two frags sitting on the sand bed right now and they are doing fine.
The dimensions of the tank are 60L x 20H x 18W.
<Your lighting in lieu of your tank depth and length is borderline at best for keeping Hammer Corals
or most other Euphyllias. The lighting should be fine for the Duncan Coral providing it is somewhere near
mid level of the aquarium. May want to read/learn more about the Euphylliidae family here.
Do read here also. http://www.wetwebmedia.com/cnidcompfaqs.htm >
Thank you so much for your help
<You're welcome. James (Salty Dog)>
Re Zoas Not Opening 4/22/10 - 4/23/10
Hi Jim,
Right after I sent my last e-mail I noticed my mistake about the magnesium level. So I guess I am a little bit on the lower end. We have had the Hammer for about six months and it's been doing great so far. After the
clowns have hosted a beautiful Goniopora partially to death. I am thinking that they are going for the hammer now. I just haven't caught them red finned yet.
<Yes, clownfish can aggravate the corals for sure.>
Sorry about the lighting information. I just looked at the lights but am not so good with the technical stuff. The other half knows everything about that and he's not here at the moment.
<No problem, the T5's are pretty intense and just may provide enough light for the Hammer Coral to photosynthesize.>
I will try to move the frags around a little to see if that will help then also start thinking for a solution for the clowns if they are hosting a coral again.
<Yes, and again, allow at least 6 inches around the Hammer Coral. The sweeper tentacles are capable of extending to that length.>
Thanks again,

Re : Yellow Polyp Unhappy/ Not enough info 3/7/10
Today the polyp seemed to look better.....but can you help explain what to really look for in lighting and bulbs, because all the LFS talks about is wattage, but T5s and others may produce the same light as a higher wattage bulb of a different type. So what are you really looking for??
< Lighting really depends on what you are planning to keep, depth of your aquarium and placement of the animals. As a rule of thumb T5's would be my choice for animals with high to medium light requirements in a tank (or placed) less than 20" deep. Animals with high light needs kept at greater depths will require metal halides. Wattage is a measure of electricity used by the light. Although it does give an indication of depth of penetration it is not a good measure of applicable light. More important measures of aquarium lighting are Lumens, PAR and Kelvin. For an explanation of these please read:
Nikki, I apologize for the long delay in my response. Seems I overlooked your email. Please forgive. GA Jenkins

hey guys, got a zoo question... beh. 9/21/09
Hey to all of you at WWM, you all have been a huge help with my tank.
I looked over the site and I may have missed it due the sheer amount of information you all provide. OK, lets get straight to the point. I purchased a nice sized frag of some really pretty rd/orange Zoanthids and there were a couple green Zoanthids in the mix. I recently noticed that the frag was turned over and was resting well in range of my torch (poor Zoanthids) so I averted them and placed them back in a more sturdy place so my Mexican turbo wouldn't move them when he goes by. (I am just assuming it was him, he's
pretty big) Of course they were all closed up so I really did not think anything of it, I figured they would open up after a while which they did but 90% of the frag is now the green Zoanthids. Will Zoas change colors or something like that?
<Yes; can, will given differing conditions>
It's not like they died and then re-grew, one day they were red with grey centers and orange outer rig, the next they were lime green... There are still a few of the red ones but the mouths are sticking
up really far almost like a little spike and very dark. I have included a pic of what the frag used to look like, you can see one of the green Zoas almost in the center of it. thanks in advance for any help you can provide.
Ryan S.
<And in the presence of competing Cnidarians... Please read here:
Bob Fenner>

Zoanthids, beh. 9/20/09
I have a small colony of Zoanthids that I just got a few days ago. On one of the sides of the rock there is a while slime covering some of the polyps. When it is touched it just goes away.
<Do thoroughly wash your hands (soap and warm water) after touching Zoanthids...>
The rock that is on smells bad so I thought it was some sort of die off from moving it to my tank but the polyps under the slime seem to be ok. The rest of the colony is happy and opening great. Please help!
<Very likely this "slime" is not problematical. These animals do shed such given changes in conditions of sorts. Best to siphon away to waste. Bob Fenner>

Tall Zoanthids, beh. 8/19/09
Hi, I've had a 90 gallon marine tank for over six months now. the occupants are 2 ocellaris clown fish, 1 tomato clown, one maze brain coral and two Zoanthid frags (I'm stocking slowly). lighting is one 12k t8, one 6k t5 and 1 actinic. all parameters are fine,
I have a AZoo skimmer, a Resun chiller (tank temp 26c) and lots of live rock.
The fish and corals are doing great but recently I noticed some of the Zoas have grown really tall (nearly 1 1/2inch) than the rest of the colony.
at first I thought it was lack of light,
<Or next, food>
the tank is 2feet deep but the Zoas have been placed right on top of the rocks since the time I got them (4 months ago). In the last few days they've swaying in the powerhead current and looking loose like they are coming off (the powerhead is not directly on them). what could the reason be?
<Lack of nutrient most likely>
Thanks Sid
<Though there could be some chemical/physical aspect of water quality lacking, amiss, a negative interaction with other Cnidarians... Read here:
and the linked files above. Bob Fenner>

Palythoa Polyps Shrinking 5/19/09
I have a lovely brown/pink Palythoa introduced to my 29-gallon cube about 5 weeks ago. The 8-polyp frag was initially very healthy - large heads approximately 1 cm in diameter, thick 3/4 inch long stalks and plump interconnecting mat fibers.
< Sounds nice. I'm a big Palythoa fan myself. >
I placed the colony near the bottom of the aquarium in a well lit area with good flow. The polyps responded well and accepted food readily. Within 10 days, the colony started reproducing rapidly, sprouting five new polyps that grew very quickly. Success - until about two weeks ago.
Very gradually, the polyps have started to shrink considerably - not retract, but actually physically shrink. Heads are now just 1/2 cm in diameter, the stalks have thinned and shortened and interconnecting mats have thinned. The healthiest polyp has actually grown up an adjoining rock approximately an inch and attached itself quite securely. I'm lighting with a single 40 watt 10 K and actinic compact fluorescent and all water parameters seem in order. I have added a second single tube standard 15-watt 50/50 10 K florescent and increased lighting hours hoping that this might be a lighting issue. My three other small Zoanthid colonies are thriving and growing - only this small Paly colony seems affected. So, some specific questions:
1) Does this sound like a lighting issue and does the colony simply need to be moved up to the top third of the tank, or is it more likely a nutrition/feeding deficiency that is causing this shrinkage?
< It does sound like a lighting issue. I would move the colony up closer to the light. If you do not see an improvement you may want to consider a lighting upgrade. >
2) If a move is in order, can I safely sever the now very thin mat connection with the "polyp on the move" with a razor while in the tank to allow movement of the main colony? It is not feasible to remove the two rocks and perform the surgery outside of the main system.
< Yes , you can use a clean razor to sever the mat. Please use caution when handling/cutting them. Some people have had extreme reactions to the toxins present in Zoanthids/Palythoas.
GA Jenkins >

Button Polyps, hlth., beh. 04/02/09
Yesterday I visited my local LFS to have a look at there marine tanks. They have only been keeping marine fish for about a year, and only have 2 small tanks.
About a month ago they bought in a piece of star polyp, a button polyp and a white toadstool. At first they looked ok then after a week the star polyps started to disappear, the button polyp has stayed closed since, and the toadstool has got a tear in the middle of it, and has gone grey around bits of the edge.
I asked the girl in the shop what had happened to them but she did not know, all she said was that this is the second lot of corals that she has had in, the first lot all died. At first she did have them in a tank with a lemon
peel, I did tell her that the lemon peel would eat them, then she put them in the other tank with a Eiblii angel. I suggested to her that I take them home and see if they would recover in my tank, with better lighting and more water flow, which she agreed to.
<That was nice of you.>
When I got the button polyps home, I noticed that they looked as if they were covered in a hard clear coating like varnish, when I put them in the tank some of this coating started to come off, it just looked like clear egg shells lifting off and floating in the water, do you know what this might be?
<The animal is disintegrating/dying.>
Half the rock that the star polyps were on is covered in coralline algae and the half that the polyps were on is all brown, like fine algae, as the evening went on I did notice small light coloured stalks appear through the
brown muck, so hopefully they might re appear, what do you think?
<It sounds like the coral might still be alive... but in bad shape.>
The toad stool looks as if it is molting as there is thin bits like skin coming off.
<It could be shedding due to stress.>
I have only had my marine tank up and running for 4 months and all the corals that I have, are growing well and looking very healthy, I could not let the corals in the shop die. There are only 2 other people on the
island that keep marines, so I had to try something, do you think I did the right thing? any help and advice would be most helpful.
<Well, it just depends... I don't usually encourage people to "rescue" LFS animals because, like any business, a LFS will keep taking in whatever it can sell (sick or not). But, if the LFS let you have these corals for free because they couldn't care for them, then I commend you for saving them without supporting a bad business practice. However, if you paid for them, I would caution you that doing so will only encourage the store to get more (without necessarily learning anything). If you want to be extra-super, you could offer to help the LFS learn how to care for these animals so that if they order any more, they will know what to do.>
Another question I have for you (sorry), I have a friend that works at a water test center, where they breed Acartia tonsa copepod and brine shrimp,
She gives me small amounts every few weeks for my tank, can I put too much Acartia in, or is there no limit to the amount that I could put in.
<Well, you can have too much of anything... I would put in as many as your fish/coral can eat and as can survive in your system without dying and causing water quality issues.>
The fish seem to love hunting them and the excess seem to crawl about the glass and on the live rock and bottom, will they do any other good in the tank, like eat some of the algae etc?
<Possibly... but I wouldn't use them for this purpose. Please see here:
Could I over feed the tank with them?
<If they're staying alive in the tank until they are eaten, then I doubt it. Again, I would only be concerned if you put sooo many in that they started to die off (without being eaten) and cause water quality issues.
But so long as they stay alive, I don't think they would be much a problem... they might even be beneficial.>
as I can get as much as I want from her. She also supplies me with Phyto plankton, how much should I put in the tank at one time? My tank is 6 x 2 x 2 and I also have a sump that holds 22 US gallons.
<Hmm, it depends on if the phytoplankton is live and if it is concentrated or not and how many filter feeders you have in the tank. In any event, I would start with small doses and slowly increase until you get the "right"
Thanks great web site
<De nada,
Sara M.>
Re: Button Polyps 04/03/09

Do you think there is no hope for the button polyps or the star?
<I do think there is hope still. I "never say never" with button polyps.
They seem to be able to come back from just about anything.>
Should I take the button out or leave it to see what happens could it affect the rest of my corals in some way if I left it?
<If your tank is larger and these are just "frags"... then the tank should be able to process any nutrients from a bit of die off. But if you think they're affecting your water quality, it's your call to remove them or not.>
I could not open the web address that you sent me about the Acartia.
<Sorry, the site seems down right now for some reason. I'd try again later.>
<De nada,
Sara M.>
Re: Button Polyps... referral? 04/03/09

The button polyps are on a rock about 4in round, they are all over the rock, there must be at least 100 polyps maybe more. Each polyp is about 3/16 of an inch in diameter, there still seems to be a bit of colour in them and you can see a hole in the center of them just like my other button polyps that I have, when they are closed at night, or if something touches them.
<These are good signs. I do think they can/will pull through with proper care.>
I will keep an eye on them, and keep my fingers crossed.
I got all the corals for nothing.
Thanks again
<Good luck,
Sara M.>
Re: Button Polyps 04/04/09

Hi Sara
This morning I had a look at the button polyps, there was a white covering all over them, looked like spiders webs. I blasted water at them with a syringe and blow most of it off. Early this evening I was looking at them again, and around the one side there are about 10 polyps open, looking better than the last few days.
<good to hear>
The phytoplankton that I get is live, it is a mixture of 2 types, not sure which types they are.
The last 2 time I only asked for 100mls and add 50 to the tank at the time,
<This should be fine.>
and add some to the sump. Is this too much to add at one time? Could the phyto add to the growth of algae in the tank?
<It could if either 1) the culture is high in nutrients or 2) if you don't have enough filter feeding organisms to consume it and it dies. But I think you're safe with those small doses.>
Sara M.>

Polyps releasing waste 4/2/09
<Hello, Jessy here>
I really need some help please. My colony of orange/brown button polyps has tonight started to release a black thread like material from each of its openings (mouths). It seems to look like thin strands of ink, thicker in some parts, but it does not appear to be a living creature like a worm.
The material breaks off eventually and is sticking to the live rocks.
Could this be reproductive material or waste or the release of toxic substances?
<This is just the waste of the polyps. No harm at all. Just polyp poop :)>
Thank you.
<Regards, Jessy>

Button polyps... beh. 12/11/08 I don't really have any info about lighting and such (I inherited the whole set up from my sister and she didn't have all the necessities and I've been playing catch up). I was just wondering what is going on with this one (see pic). It seems to be blowing up like a balloon, all of the surrounding polyps are doing just fine. I've had the set up for about 6 weeks, and the dwarf fuzzy lion, mushrooms and other little critters don't seem to be affected. Any ideas? <Mmm, might be "normal", as in natural behavior... Zoanthids just "do" this... self-cleaning, digestion... Could be a negative chemical reaction with the Mushrooms... Please read here: http://wetwebmedia.com/cnidcompppt.htm and the linked files above... Bob Fenner>

Renegade Polyp -?! 03/17/08 I have switched from a 15W 50/50 single light tube to a 65W Compact Fluorescent 50/50 light. One of my polyps is behaving weird. <Like a colon polyp?> The behavior began since the day I got the group. The polyp has its mouth completely exposed and the oral disk is folded backwards. All the other polyps are fine. Do you know if this could be a problem for the animal in the future? It seems healthy. <Group of what? What type of coral/animal are we talking about here?> Water parameters are 0 ammonia, nitrite, 0.05 nitrate, 8.4pH, 78F Thank you. <Best, Sara M.>

Re: Renegade Polyp -03/18/08 Sorry, I have a group of button polyps. <Hmm, since it's just one polyp I wouldn't worry about it. Sometimes these animals behave a bit oddly for no apparent reason. If the rest of the colony is doing well and you can't find anything wrong with your water quality, I'd just shrug it off and see if it doesn't go back to normal eventually. Best, Sara M.>

Orange Zoanthids Closed Up 2/16/08 Hello Crew, <Dave> I have a small colony of bright orange Zoanthids that I have had in my tank for about four weeks now. This week they have been entirely closed up and look to be shrinking in on themselves. I am trying to find out the cause. Previously they were open with nice large polyps and doing well. They are placed in the sand bed in an area in with high water flow. The other Zoanthids in this area seem to grow the best here. <This is "it"> I have fifteen other different color Zoanthids and they are all doing extremely well. The rest of the reef tank is doing great as well. I have read the Zoanthid articles listed on your site, but none seem to help out. I was also thinking that it could possibly be allelopathy, <Allelopathy> except all the other Zoanthids are doing great. I would really like to recover these Zoanthids since the orange ones seem to be rare and they cost me over $200 for just ten polyps. Would it be in my best interest to move them to another friend's reef tank? <Yes> There doesn't seem to be any foul play from snails or crabs, and I don't see why only this Zoanthid colony would be singled out. I also didn't want to move them around since they are already stressed. <Is just a "loser" under the conditions present... to the more vigorous Cnidarians present> About my tank: My 125 gallon reef has been established for almost eight years now. I have 6 six foot VHO bulbs. three actinic and three aqua suns. Two main pumps 1800 and 1200 gph. They are controlled via two SCWDs and four returns. The actinic lights come on an hour before and after the main lights. Temp is between 76 - 78 degrees. I have a wet dry sump, but have ordered a 45 gallon ADHI refugium. For the time being I have a small basket of Chaeto algae in the main tank for nutrient control. 15 gallon water changes are done weekly. I am using an AquaFX RO/DI system for RO water. Salinity level is at 1.025; PH 7.8; Nitrates and Nitrites are at 0. Alkalinity is a little on the low side. I am starting to use a buffer to bring it up. Let me know if there is anything I am overlooking. Thanks in advance! Dave <You might be able to "classically condition" these Zoanthids to "getting along with each other better". Read here: http://wetwebmedia.com/cnidcompppt.htm Bob Fenner>

Zoanthid Colony Not Opening 11/14/2007 <Hi Carla, Mich here.> I recently purchased a small Zoanthid colony of roughly 15 polyps from a fish store in Bowling Green, about an hour from where I live. None of the polyps are opening and I am just wondering if it is dying or if these things can actually be "shy". <Can take a bit of time to open, perhaps they are not getting enough water flow.> Also if it is dying is it something wrong with my water parameters, lighting, temperature, <You never mention your water temp.> or something else. also what kind of chemicals can I purchase to better improve my water quality and the health of my fish? <Ho buoy... Where to start? You need to change your thinking. Adding chemicals won't improve your water quality or the health of your fish. Good husbandry will improve your water quality. Frequent water changes will go a long way here. Some good tips here: http://www.wetwebmedia.com/scottsh2ochgart.htm http://www.wetwebmedia.com/watchgantart.htm http://www.wetwebmedia.com/water.htm http://www.wetwebmedia.com/nutrientcontrol.htm > Here is my tank Info: 20G/L, 20lbs of live rock, 4 hermit crabs, 2 clown fish (A. Ocellaris), and my little Zoanthid colony. I have a Taam Rio Nano Skimmer, and for lighting I have a 36 inch Aqualight with a 96 watt 10,000K Daylight bulb and a 96 watt True Actinic 03 Blue Bulb. The light fixture hangs about 2 inches from the surface of the water. <Sounds good.> My water parameters are a specific Gravity of 1.025, Ammonia 0, Nitrite 0, Nitrate 0, <Sounds good.> and a PH of 8.8. <pH 8.8?!?!?! Is this really what you meant to type? Is high! If true could be making your Zoanthids unhappy!> I looked thorough the FAQs and honestly there are just too many to read all of them. (Which I think is a good thing cause that means a lot of people put their trust in you!) <Yes, but there is much good information here if you take the time to look.> Thank you for your time, <Happy to help.> WWM is like a best friend that happens to know a lot about Aquariums!! <Heehee! Nice to hear! Some of my best friends are here!> Sincerely, Carla <Cheers, Mich>

Re: Zoanthid Closure 11/15/2007 Hi Mich, <Hi Peggy> Thanks for replying to my questions. <You're welcome! I'm happy to help.> I will try larger water changes on a weekly basis. I noticed for the second time that one of my power sweeps is stopping. If I take it out and scrub where it rotates it works for a while, (week or so) then it stops again. <You might try soaking it in Vinegar to remove some of the mineral deposits.> I also wanted to ask you if the water movement would trouble all the zoos? <If there is insufficient water flow they may not open.> They are all in different locations. <More likely something systemic then.> I am sitting here as I write to you and watching my torch coral wave and all other inhabitants looking so beautiful. Oh yeah, yes my skimmer has always been crappy. <ScottF would suggest making it into a lava lamp!> lol .... I ordered and received a Corallife super skimmer only to find out the pump would not fit into my Aquasystem. Go figure!! <Argh!> Next step, maybe a bigger tank with a bigger sump area. What do you think? <Ooooh! Bigger! Go bigger! Go bigger!> How long can my zoo colonies stay closed before they begin to die? <Actually quite some time. You would probably be surprised. They will start to shrink in upon themselves over time.> Will the water changes bring my calcium and stuff up or do I still need to use additives? <Generally all but calcium and Alkalinity can be maintained by water changes. The easiest was to supplement these is with a two part additive such as B-ionic. More here: http://www.wetwebmedia.com/caalkprods.htm http://www.wetwebmedia.com/calcalkmar.htm http://www.wetwebmedia.com/mphprods.htm > You know how confusing it can be. <Yes, I do.> Some people on the fish/reef forums swear by them. <Unfortunately there are a lot of worthless products out there.> Thanks for your info and help. <Welcome! Mich>

Zoanthid Closure beh. 11/11/07 <Hi Peggy, Mich here.> I have a question please. <I have an answer thank you! Heehee!> I have four different colonies of Zoanthids. They used to open up every day until about 2 1/2 weeks ago. They closed up and have remained closed up ever since. I have a 55 gallon established reef tank. I do four-gallon water changes weekly, but nothing has helped. I have two stony SPS corals, one torch, some mushrooms, xenia, one brain, a long tentacle mushroom, some star polyps and a large Elk Horn coral. I have been reading on your site that there can be warfare between these creatures. <There is lots of potential for allelopathy in your system.> Does this just all of a sudden happen? <Depends...> I have two power sweeps in my tank and one powerhead under the rock in the corner of my tank. I have an Aquasystem on my tank with a crappy skimmer. The skimmer has always been crappy, even before this problem. <So you're saying it's consistently crappy... Heehee!> I dose with Kalkwasser by IV drip method and I add strontium, reef builder, phytoplankton bi-weekly and iodine every other week. My tank parameters are as follows. <Mmm, I'd be more inclined to rely on larger weekly water changes than all these supplementations.> PH 8.1 low SG 1.024 Temp 76 nitrite 0 nitrate 0 ammonia 0 dKH 15 (perhaps high)<target range is 7-10 dKH> cal 400 (low) Mag around 1240 What do you think is going on? Everyone else is doing great!! I hope you can shed some light on this problem. I have checked with a magnifying glass and see no bugs or abundant algae covering them. What's up? <I have had a similar experience when the my water movement was unknowingly reduced. Perhaps one of you powerheads is not operating properly. I would check the water flow in your system. You could also try moving one of the cluster to an area of high water flow and see if this makes a difference.>> Thanks Peggy <Welcome! Mich>

Re: Toadstool Leather Coral... Now Zo's beh. 10/30/07I bought some yellow polyps the same day as well and they are fully open but they are green, are they getting used to the tank as well? <<Kane: Depending on the lighting, Yellow Polyps can look Yellow or Yellow-Green. The fact that they are open is a good sign. Polyps can take several days to adjust as well. I find them to be very hardy and fast growers. Best of luck, Roy>>

Zoanthid Question... beh. 2/19/07 Hi Crew, <Sammy> I have a 10 gallon with some fish and mushrooms and 2 Zoanthid colonies. Since my tank is just 10 gallons I spend a lot of time studying what little is in there. One colony has almost no skirt and the center is blue and yellow. It has not grown much since I got it. The second one has a red/orange skirt with an orange and yellow center. This one started with 12 polyps and now is over 35. I also cut off 3 polyps, placed them on a small rock and in 3 weeks there are now 7 polyps. But what I find interesting about this one is that the size of the skirt grows. When I got it the skirt was very short and as time went on it go longer until it looked like long curly red hair. Then the polyps closed up for a couple of days. When it reopened the skirt was short again. And the cycle started over again. It has done this 3 times already. I never read about this and I am sure I do not have a unique species. I was just curious if anyone else had noticed this. <Not unusual to see reactions like these, especially in small tanks where water parameters can change quickly. James (Salty Dog)>

Button polyps beh. 9/18/06 Hi there... <Yo there> I've got a quick question for you and I can't find an answer to on the site any where. I purchased some button polyps a few weeks ago from the local shop and since then the tentacles on all these little dudes have grown in length by about 4 to 5 times what they should be. <"Looking" for something... food? Other cnidarians?> Their <They're> starting to out grow each other and I just doesn't seem very attractive. my tank setup is 40 gallons with 2x96 watt 10K and one true actinic 96 watt light all less than 6 months old. Any thoughts..... I can't find the answer. thanks Chad <Please read here: http://www.wetwebmedia.com/zoanthidbehfaqs.htm and the linked files above. Bob Fenner>

Zoanthids close as soon as daylights come on 9/9/06 Hello. I have searched high and low and can't figure out why my Zoanthids will fully open when the blue lights come on in the morning (I have the blues on for about an hour before the daylights come on). Then as soon as the daylights come on, the Zoanthids close up for about 4 hours before they open back up. This is only something they have been doing for the past month or so. I do regular water changes every week, usually 15-20 gallons in my 75 gallon tank. I don't know if I should be alarmed since they open nicely before the daylights come on? Thanks in advance, Kelly <Their opening/closing behavior correlates with the availability of food organisms, predators in the wild... do become otherwise photo-behaviorally adapted in captivity in time. No worries. Bob Fenner>

Zoanthids are Closed.. Help! 9/5/06 Hi there! I'll start with tank specs: 30 gal, temp 78, SG 1.025, Nitrate/Nitrite 0, Ammonia 0, Alk 300, <? 300 what?> pH 8.0, 192W lighting (dual daylight, dual actinic) I read through most of the Zoanthid threads, with no answer to my impending questions. My tank has been up and running since late March 06, and my Zoanthids have been happy since I bought them in May. However, around the middle of July I noticed that my Zoas were starting to close up. <Not compatible... in small volumes... even with their own Class> This may have had to do with a water change gone wrong, and I ended up having a much lower SG than I had planned. I usually kept the SG at 1.022, <Too low> and it dropped during that water change to 1.019. I slowly built the SG back up to 1.022, with no change. The Zoas remained closed. I sought help from another forum, and they suggested I raise my SG to at least 1.025; so, over a week I slowly raised my SG to 1.025. This increase was completed on Aug 7th. The Zoas have still not opened up. They don't look sickly, nor discolored, and in fact, they are still making little Zoas. Now, why wont the Zoas open up? <Allelopathy likely> What can I do to help them? <Larger system, chemical filtrant use, clean the skimmer, add a refugium, remove most of them...> I'm really disappointed that I can't seem to do anything to help the situation. I did a 30% water change Aug 3rd, and after reading a few articles, decided to do a 50% water change today (Aug 28). Still no dice. Could you please help me with what's going on? My last idea is to quarantine them in another tank, but regardless, I am at a loss as to what I should do at this point. Thank you, Stephanie <Read, re-read here: http://www.wetwebmedia.com/zoanthidcompfaqs.htm and the linked files above. Bob Fenner>

Death = Life?? Zoanthids mostly 7/7/06 Hi Crew-- <Chris> There is a very interesting tank development that i need to run by you. I bought a Zoanthus (sp?) colony <Likely a Zoanthid> about 4 weeks ago. Most of the spores <... polyps> died off the rock, except for the most mature (big) spores, and even those refused to bloom. I tried moving them lower, then higher and still nothing. They'd been untouched for about two weeks. Well, unfortunately my sleeper goby bit the dust the other day and all my hermit crabs and chocolate chip starfish took care of the carcass. I didn't perform a water change yet, and the zoo's all of a sudden have started blooming. I'm not sure about this, but is it possible that when the goby started decomposing a lot of nutrients were released into the water, and perhaps the reason my tank has not been doing all that great is that the water is *too* clean? <Mmm, possibly... but much more likely this colony just "became acclimated"...> Anyway, looking forward to your thoughts on this. A follow-up question is how can I maintain this water "quality" so that my tank thrives? <... Posted... marine filtration, maintenance... on WWM> As always, thank you. Regards, Chris Stormes <Please read here: http://www.wetwebmedia.com/marine/inverts/index.htm scroll down to the section on Zoanthids... Bob Fenner>

Question on Zoanthus sociatus not opening 3/15/06 I have a new Zoanthus sociatus (metallic green variety) colony that has been in my tank for 3 days now, and doesn't seem to want to fully open. <Three days is not very long here> the polyps are mostly open but it is not fully extended. right now the colony is on top of my rock, about 4inches from the surface, and located between the water streams - a steady but not real strong flow over it <Please read here: http://wetwebmedia.com/ca/cav1i1/blane-zoanthids/zoanthids.htm and the files linked below> I have a 29g reef, Prizm skimmer and Marineland 200 bio-wheel filter, 105w fluorescent (1x65 CP and 2x20w fluorescent). I don't test my water :-( but I do have a anemone, Haitian pink-tip <... incompatible> I believe, and he has been doing just fine for a few months so I "assume" the water quality is fine. Question is, at what point should I be concerned about the colony not opening fully, as I know there can be some acclimation, and what water flow and light intensity is best for this colony??? Patrick <Do read where you've been directed. Zoanthids in such small systems are problematical... particularly where mis-matched with other Cnidarian life. Bob Fenner>

Beh. Zoanthids 02-05-06 Hi Crew, <Hello> Recently I noticed that all of my Zoanthids have started to close up (approx 2000 polyps). I searched your website and found that sponges may contribute. I removed all of the red ball sponges, phosphate binding media, and carbon. The chemical media I recently added. I still have some chicken liver sponge. I raised my lighting. The water parameters are fine, except nitrate is between 10-20 ppm, but they should do fine in nutrient rich water. I did however raise the pH from 8.1 to 8.3. I added a dry base rock which raised the Alk to 4.4 mEq. The iodine level (Salifert kit) unreadable due to excess iodate. Does anyone have any ideas? <High levels of iodine/iodate has been noted to cause polyps to close up. Do a fairly large water change to level your parameters back out. The water change will also lower your nitrates. Try that for now. As a side note... In the future make sure to make changes slowly. That will allow your tank to adjust and make it easier for you to target causative agents when your tank has issues. Travis> thanks

Unhappy Palythoa - 12/25/2005 I recently received an 8" beautiful orangish-peach Palythoa group. While I was unloading the minivan, my wife just dumps it unceremoniously into the tank. <Yikes!> Well, the polyps close up and haven't opened since (3 days now). <Again, yikes!> They half-way open at night, but then close again when the lights start up. The water he came in has a pH of 7.7, <Yargh!> while mine is 8.0... <Still too low.> more on this later... and the temps were identical. He was only in transit for about 45 min. <These animals needed to be drip acclimated for a few to several hours.... pH shock like this is deadly. Uhh, and WHY on EARTH were they in a pH of 7.7? That's WAY too low.> He came from being at the bottom of a 29gal directly under a 150w 10000K HQI and 2x55w CFL actinics. I have 2x65w CFL super actinics (420x430) (12hrs/day) and a 250w 10000K MH (6 hrs/day). I currently have him located about 12-15" from the MH and I'm thinking he may be a bit too close, as he's more closed up once the MH comes on. However, he isn't any happier when it's just the actinics....am I right to worry? <Yes, possibly. You could consider "screening" some of the light out a bit, or raising your lights for a while.... but these animals' real problem right now is just adjusting to your water parameters. The best thing to do may simply be to wait.> As for the pH, is there anything that works better than Kent SuperBuffer for raising and maintaining the pH? <Probably best to start reading here: http://www.wetwebmedia.com/marphalk.htm , and the FAQs files linked at the top.> I have been using the recommended amount daily for about 3 weeks and my pH hasn't changed one lick. I know this pH is pretty low, especially for my anthelia and xenia. My source water is pH 7.6 but extremely soft at .5dGH and 5dKH. Any suggestions? <Start reading.... there is MUCH more archived than I could begin to tell you. Wishing you well, -Sabrina>

Hello first time question asker, very long time reader... Zoanthid negative reaction 12/22/2005 Dear Bob, <Scott> I can't believe that I am actually writing to you! I have been reading your stuff for over two years. Voyeur if you will. Finally time to ask you a real question. <Pleased to meet you Scotter> Having read some many of your responses, I have a pretty good idea of how you think ( in a sort of cumulative way). So please understand that I have broken some rules and followed most. <Of course> Space limitations have made it necessary for me to only have a 29 Gal with a 20 gal sump. Ironic, since money is not an issue. What this has done, has made me focus on optimization and quality. <Good adverbs> It turns out that this has had its benefits. As a result, I have been artificially forced to get away from the "great big tank" syndrome. This may have been a kind of strange blessing. My tank is about 2.5 years old (ancient history - I had a 150 gal marine tank for five years in the early 80s back when the idea of keeping live coral was impossible and the latest technology was putting powerheads on UG filter lift tubes). Water parameters all optimal. System has two urchin skimmers, wet / dry trickle ( home made with a few bioballs and more chunk coral), two power heads with foam filters, chiller / UV with 150 gph Mag pump, and last but not least, two of the hang on the back (can't remember the manuf.) larger box filters. Collectively, I have over killed the water movement and filtration. Lighting is 3 55/65 w power compacts. Finally, I regularly change carbon (two weeks) and use poly filters religiously (two weeks). <There are moments when I wish I owned Poly-Bio-Marine...> One of your best ideas, that I have incorporated into the system was to take the side of my 20L sump directly below the trickle and build a "one third of the way up" glass divider wall to create a 12" X 14" deep sand bed ( about 4" deep). When I did this, substantial drop in nitrates. I give you full credit for this. <Thanks. I give you at least partial credit for "doing it"> Finally, lots of live rock (can't tell you how much). Long and short, extremely stable system. I have raised and sold back to by LFS from this system a number of specimens ( I take a lot of pride in being able to bring things in, grow them up and pass them along) <An admirable action> So much for setting the stage. And finally to my question (whew! Bet you thought I would never get there). For many months, I have had a colony of Protopalythoa sp or thereabouts. These were thriving, growing, expanding looking really healthy for a long time. However, big change recently. We went from growing thriving, to barely making it ( looking closed up etc). Only two variables in the equation - 1. Introduction of a small colony of Goniopora on the other side of the tank (I know, I know but it was cheap, lime green, and really pretty), <This would do it...> and 2. I bought a small Imperator angel, who was very young ( maybe 1.5 inches at the time), who has since grown. Before you say it, the angel will either go back to the LFS or into a bigger tank next year. <Good> What's killing the coral - the angel or the Goniopora? <If of these two, the Poritid> I fully understand that it might be either, have seen the angel nipping, but not a lot. Your take??? <Is the Flower Pot> PS: also have frilly mushroom, large finger leather, mother and three kids BTAs and yellow polyps. No other known "coral eaters" in the system. <If you are keen to grow the other cnidarians... you already had/have... I would not attempt to add others here. Though you use chemical filtration, are likely rigorous in other maintenance, this allelopathy will be problematical. Bob Fenner>

My Zoanthids are turning white - 10/19/2005 HI, <Hello Paul> I'm a newbie to reef keeping. I've had a fish only marine tank before but now I've decided to move onto reef tanks. Currently my tank is 4 month old and I have four fishes and various Zoanthids and mushrooms. Following is my tank parameters: pH=8.3, ammonia=0, nitrite=0, nitrate=0, alkalinity=3.5meq, calcium=340 question I have is related to my Zoa. I've had them for about a few months now and recently noticed that the oral disk on the Zoa are turning white.<A sure sign of stress.> I've read that this is due to too much light <not necessarily> but I only have about 3.7 watts per gallon and I have all my Zo's on the lower half of the tank. Tank is 75 gallon. Please help. Thanks. <Paul, please capitalize proper nouns and beginnings of sentences in the future. That said, back to business. The oral disks are turning white because they are expelling their zooxanthellae. Too much light can cause this but is not the only factor. There is not enough info on your tank to be certain what is causing this. What is your temp.? Salinity? Are the mushrooms touching them? Try moving your Zoanthids further up in the tank (maybe midway though mine prefer the top). The only absolute here is that they are not happy with their present environment. - Josh> Paul

Worms - 07/19/05 Sorry to bother you. <<No bother>> I usually find what I'm looking for on your site, but I'm not entirely certain this time. <<ok>> I have a 45 gallon reef tank (teeming with live rock, mushrooms, polyps, frogspawn, feather dusters, 7 shrimp (1 pistol hitchhiker), porcelain crabs, snails and 6 fish (yellow tang, pink Pseudochromis, blue damsel, false percula, brown barred goby, jeweled rock skipper). Yes, I know, probably over-populated. <<Yes...please consider finding another home for the tang...>>>> The wet-dry is for a 75 gal. tank, the protein skimmer is good and there are several powerheads in the tank for circulation. I clean the tank and protein skimmer, change the filter pad and perform a 13 gallon water change weekly and the water quality is fine. <<Very good! I love to see people doing "weekly" maintenance.>> Everything in the tank is thriving and I'm not over-feeding. However, the last time I added a button polyp, within a few days what appeared to be intestines (white, curly, gross) appeared in several spots, on the polyp itself and on the wall of the tank. <<Possibly mesenterial filaments (digestive organs) from a defense response as a result of stress.>> Within a day or so, they disappeared. <<Yep>> Then I noticed tiny little clear shrimp-y looking things on the filter pad when I change it, and several long, thin, white worm-y looking things in the bottom of the wet-dry. I haven't seen any of these things in the tank itself, however, but it seems that there are more of them each week in the filter. <<Probably amphipods and bristle worms, beneficial detritus feeders... Though you haven't seen them they are in your tank (came from/live in and around your live rock, and as you are discovering, will also accumulate in your filters.>> I'm wondering if I should be concerned or not.. <<Don't worry...be happy... (do I hear music?)>> I'm also curious as to where they came from - are they hitchhikers? <<Yes...hitchhikers from the live rock.>> Thanks. Emily <<Regards, Eric R.>>

Zoanthid Q Hi Crew, <How goes it?> You have a fantastic site here, I've learned a lot just reading the different posts. First let me give you my equipment setup. I have a 29g tank with the following: CPR Bak-Pak2 skimmer Bio-wheel 125 filter 2-Rio 600 powerheads 1-Powersweep powerhead 220 watts power compact lighting(110w 10,000k/110w bright blue actinic) 45lbs live rock 1 1/2" to 2" of crushed coral and I do 15% water change every 2 weeks Live stock includes 12 Astrea snails 6 Bumblebee snails 12 hermit crabs <Looks like your message was truncated, but judging by the subject you were wondering why your Zoanthids weren't opening. If you've just introduced them, give them up to a week to acclimate. If not, be sure to check all of your water parameters. Zoanthids are tough and don't stop opening for no reason! M. Maddox>

Unhappy Zoanthids 1/28/05 Hi Crew, Recently my Zoanthid polyps have been unhappy and I'm not sure why. I have a few guesses but I'd like your input. I recently purchased a refractometer for my young reef. (1yr). I calibrated and measured and got a reading of 1.027. Id like it at 1.025 so during my last 2 weekly 10% water changes I added water at 1.025. and slow dripped some fresh RODI to bring it to 1.025 over 2 weeks. <Good conservative technique. No problems here.> I have used oceanic salt for the last 6 months with no problems but I have heard and read negative things and have had no problems so far. The other possibility is my Galaxea which is a good 14-15" away from the nearest polyps has been real aggressive lately. It's sweepers at times very excited and extended. could it be affecting the polyps? I also have star polyps, a hammer coral, and got a cap Montipora 2 months ago which has doubled in size. Only the zos are affected. Ph is 8.1 and has been forever, calcium is a little high at 450. Alk is 3.1 KH is 8.5 which is a little lower than usual but acceptable. Phos was undetectable. what do you think?? <Aggression from your other corals is certainly a possibility. The low alkalinity (a common problem with Oceanic salt) may also be contributing. You did not describe how much current you have in your tank, and water movement is very important. Do also be sure to rule out picking by any fish. Good luck! AdamC.>

Inside-Out Polyp 12/16/04 Hi, I hope you can help me understand why my polyp is doing this. Tank Parameter: 30 gallon Breeder pH 8.0 KH 12-13dH Calcium 460ppm Nitrate 20 ppm Nitrite 0 ppm Ammonia 0.25ppm Lighting: PC 96W : NO 80W = 5.8W/G That will increase once we get the additional PC (192W). SeaClone Protein Skimmer (I know this is not the best but it works for me) <Don't fix it if it ain't broke! Sounds like plenty of light for most animals.> Getting to the polyp, I got this polyp when I got the live rock to I don't know that type it is. But I believe it is some type of button polyp. Yet all the button polyp that I have seen have been smaller than this one. When it was open it is about the size of a nickel. But for the past week it has been closed up inside out. The one on the top right has stay like that all day and all night. The one on the left bottom that looks like a doughnut does come out of it once but has started to stay that way longer. <Some "Button Polyps" are quite large (up to about 2" across). They will open and close for a variety of reasons, but usually some kind of irritation (over-illumination, picking by crabs, shrimp or fish, etc.). I would try and rule out some kind of physical irritation.> If you need additional information, please feel free to ask. Kit <If you can't figure out what it might be, do consider sending a list of tankmates. I am also concerned about the fact that you have detectible ammonia. Please verify this on a different test kit. If the repeat test confirms the presence of ammonia, you have a biological filtration problem. Best Regards. AdamC.>

What is this string stuff on my polyps? I got home this evening, and when I looked at my tank I noticed that many of my Zoanthid polyps had reddish brown string coming from the center of each polyp. << Probably releasing a slime coat. >> These are fairly new colonies. The first few days in quarantine, I noticed several Nudibranchs on them, which I picked off with tweezers. After several more days, they were all open and looking great. Now a week later I noticed these string looking things, and some look as though they have been eaten to a nub. << Well usually they release slime coats to remove detritus on them, or expel waste, or who knows what else. But it is common, and probably not a problem. >> Any ideas on the problem, and what I might do to get rid of it/them. These are good size colonies with 40-50 polyps. << I would increase water flow near them. This can help bring them more food, remove waste, and prevent sedimentation. Other than that, it sounds quite normal so I wouldn't worry. >> Thanks << Blundell >>

Zoos Quietly Trumpeting? Hello, <Hi, Ryan with you today> I recently purchased colony polyps (Zoanthus sp.) about a month and a half ago. My water parameters are like so: PH - 8.2 Salinity - 1.025 Temp - 80 degrees Ammonia - .25 <Why?> Nitrites & Nitrates - 0 Phosphates - 0.2 <Why?> I have about 100 lbs. of live rock, 40 lbs. of live sand, and I do a 10% water change each week. It is a 46 gallon tank that is home only to 2 clown fish and has been up and running since January of this year. <Is your circulation OK? I'm not understanding what is causing this ammonia spike> Just recently, I've started using RO water for top offs and water changes. I have 2 maxi 1200 providing current, with a Prizm skimmer and a emperor 280 using SeaChem's Purigen and PhosGuard. Lighting is a custom SeaLife 192 watt power compact. I have been using the GARF method for coralline algae growth and other than the colony polyps, I have starburst polyps and cabbage coral. <OK- You're either going to need to step up the circulation a little bit, or add a larger skimmer. The water isn't being turned over enough, and the Maxi-Jets can't cover 100 pounds of live rock properly.> My question is that when I purchased the colony polyps at the store, they looked healthy and "button" like. Ever since I've brought them home, they have looked more "vase" shaped. I have tried positioning them on all different levels, so that they could return to their "button" shape, but I have had no luck. I was wondering if there is something that I am doing wrong? I know the LFS had them at the bottom of their display tank utilizing metal halides. I've recently repositioned them to the bottom, and they still have a "vase" shape. Enclosed are a couple of pictures of what mine look like, and a picture I found on the web showing you what they looked like at the LFS. Please help! Thank you much in advance! <They're going to need to adjust to PC lighting- They likely were in full sunlight just a few months ago, then were under MH for some time at the LFS. They're stretching to make better use of the available light, to prevent expelling their symbiotic algae and therefore hindering growth rates. I would move them to the top 10 inches of water, and expect to see them trumpet a bit until the ratio of available light to symbiotic algae evens itself out. Good luck, be patient. Ryan> Jeff

Zoanthid poison 4/25/04 Hi Crew ! <cheers, my friend> Just another quick question .. how do Zoanthids release their palytoxin poison? <can be exuded separately, can be carried with mucous... and can simply be ingested by things that should not eat it. Palythoa toxica of Hawaiian waters was used in time past by natives to tip spears for mortal combat. Its a serious neurotoxin> is it through stinging or by being cut when being trimmed? <the latter more so... and be sure that you always wear gloves when working in the tank with corals and especially propagating them> I'm studying the different corals to choose which to stock. I've removed the Euphyllias from the list as they are toxic and give out serious stings to people. Could you give some suggestions on "safe" corals ? <please do not stock your tank this way... you will have almost nothing in it. A majority of sessile invertebrates (corals, sponges, tunicates, etc) have some means of noxious chemical defense. DO focus instead on collecting a natural selection of species form the same niche/biotope> Thanks for all the help, you're site is the best. Romel <best of luck, Anthony>

Re: Buttons / Mushrooms Well I was sitting watching my first addition to my (hopefully) newly started reef tank. Last night, as posted earlier my green buttons started curling up...I realize now this is normal from the stress of the move. This rock with four buttons is just my first piece to test the tank. Anyhow, all was good but when I fed the few fish in the tank, blenny and few damsels I cycled it with, the buttons started to curl back up, but very tight. I only fed a small piece of frozen brine shrimp to the damsels. Well the buttons shriveled up so tight, from the size of a half dollar to the size of a dime. They then started to secrete a white stringy material from their centers. Only 2 of the four did this. The small tentacles on the buttons swelled as if they were going to burst. I did an emergency water change of about 15%. All tests were fine except pH a little low. I have no idea what happened and was hoping that someone else might have had experience with the same fate. Are these buttons dead now...I've just left them to see. Any info would be appreciated. <Boy John, relax it's alright. It is normal for Zoanthids and mushroom/Corallimorphs to change size and shape and to react to food and sometimes movement in the water from fish, etc. Your water is likely fine and in a new tank, a slightly depressed pH isn't all bad, i.e.: ammonia toxicity. If you have the proper lighting and water movement it is unlikely anything negative has happened to your new inhabitants. These are some of the hardiest of all captive corals. This is the first of many such experiences, more than you can imagine! Don't hesitate to write to us again if you have any other questions. Enjoy! Craig>

Polyps not opening and snail development The polyps in my tank have stopped opening up all the way. But the two anemones in the tank are opening up fine. My specific gravity is 1.025, my ammonia is 0, nitrite is 0 and nitrate is low. Temp is 80. the lighting comes from a pair of power compacts, one day and one blue. Could it be that the lighting is too strong? <No> Or is it the pH? <I doubt it> My pH test had expired, is it still good to use? <Probably> The fish seem to be doing fine. <No doubt> One more question? How long does it take turbo snails to develop? <Develop? You mean to get bigger? Should be continuous, linear with time> My tank is covered in mini snails, but they don't seem to be moving? <Probably not what they appear to be> >> There is likely a negative interaction between your Anemones and polyps... I would institute monthly use of a chemical filtrant (like activated carbon) in the filter flow path... and do a large (25%) water change in the meanwhile. Bob Fenner

Zoanthid sweepers? Hello again, <Hey, Pinky.... where you been? :) Missed ya!> As far as I know, Zoanthids don't have sweepers. <agreed... no large structures like we see/think of with other corals> So, you can imagine my surprise when I saw what appear to be sweepers coming out of them. While not entirely clear from the picture, these do come directly out of the animals mouth. I initially thought it might be some sort of worm (saw a feeding arm from a spaghetti worm), but coming out of the corals mouth, well, it certainly looks like a sweeper to me. <tough to say what these are from the picture alone. The color looks rather like the Zoanthid color. That would be odd for a sweeper whose primary function is defense (no wasted energy on Zooxanthellate or reflective pigments expected here). I wonder if these aren't strand of expelled zooxanthellae? Just speculating here. Unless you are seeing them very regularly? Hmmm... interesting. Do take and share better pics if you can. Thanks :) Anthony>

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