Zoa problems


New Member
Hello all,

I am new to this forum but I have had a tank for about 10 months now. I am having some issues with a couple different species of Zoas. It seems like some of the polyps are dying off. I sometimes find heads that are floating around the tank. They appear as though they were pinched off. I have some that have not opened at all for about 2 weeks. The rock I have has a variety of zoas and most of them look to be doing well and thriving. I have one rock colony that appeared as though it may have had a fungus so I dipped it in Reef Dip by Seachem. This colony seems to be doing better since the dip a week ago. The colony that I am having problems with now does not appear to have any fungus on it nor any spots that would suggest pox. I do not have any nudibranches that I can tell. I have looked at night with the lights off for an hour or more using a flashlight. I do have many asterina starfish in there and sometimes they are in the zoas but I don't believe they are eating them. I have included a couple of photos, my tank parameters, and my stock list below. Any suggestions? I would obviously like to save the colony if possible. I am thinking of doing a coral dip or freshwater dip on the colony I am currently having issues with but it will be a pain for me to get them out of the tank.

My tank parameters are

Temp 79.5
Alkalinity 9
Ph 8.2
Ammonia 0
Nitrites 0
Nitrates 3-5
Phosphates 0
Calcium 420

I use the Kessil Tuna Blue 350w for my light source. I don't have any filtration except for live rock/sand and 20% water changes every 7 days. I add Brightwell Aquatics Nano Code A and B as needed. A is not often and B is every other day. I use Instant Ocean Reef Salt.

Stock List
Lavender mushroom
Star polyp
Waving Xenia
Pulsing Xenia
Orange montipora
Jedi mind trick
Unidentified acro
B&W clownfish
Pajama Cardinal fish
Peppermint shrimp
Bunch of hermits and snails

Please help. Any and all suggestions or tips would be greatly appreciated. Thanks.



New Member

The corals were looking worse this morning and since I have not heard any responses, I took matters into my own hands and did a coral dip and then did a freshwater dip. The zoas are back in the tank and haven't opened up yet though it has only been about an hour since the dip. Hopefully this helps. I did not see any nudibranchs come out, just some copepods, asterina starfish and small white brittle stars. I will keep everyone posted. Any tips or suggestions are also welcome.


New Member
not sure who the resident experts are anymore. I posted from back in the days in 2005/2006 I believe, lol

I did a google search for you and found this. Maybe it will help you.

1. Allelopathy.
2. Zoa pest like: Sundial Snail, Nudibranch, Zoa Spider.
3. Low nutrients (tank too clean).
4. Contaminant in the tank.
5. Skewed parameter: High Temperature, Low Salinity, High Alk, etc.

Good link: Zoanthid Predators, Irritators, & Diseases
http://www.zoaid.com/gallery2/v/zoanthi ... itemId=384


New Member
Thanks for the reply. I have researched a lot of these different things myself and I have inspected for pests and diseases. The only thing I can think is that there isn't enough nutrients in the water or Allelopathy (i have about 5 variety growing on the same rock) as you have suggested.

I feed the tank once every 3 days with a few drops of oyster feast, a few drops of mysis shrimp and a few drops of roti feast. By a few drops, I mean a very small amount. All food combined is maybe a 1/4 teaspoon. My stocking list is the same as above however I recently added a Hector's Goby and a few banded trochus snails and a couple more Nassarius snails. I may need to do a smaller water change every week or feed more with the same water changes. Thanks again for the reply.


New Member

I did some more inspections tonight with a strong magnifying glass and it appears as though I have discovered a couple of things going on. I have seen a couple of tiny snails which also appear on the glass at night. They look similar in shell shape as shown in the link you gave but they are white not colored. To treat, the link recommends to do a coral dip. I did a dip in Reef Dip Coral Disinfectant by SeaChem on 2 of my sicker looking zoas about 3 weeks ago. One colony had fungus that I started dosing first. I dipped 3 times and the eagle eye zoas looked better after about a week with no more visible fungus and new polyp growth.

I had a second colony, which I pictured above, with no visible fungus but looked like it had different issues. I dipped this coral once about 2 weeks ago and I have not seen any improvement. I plan on dosing again tomorrow. I also know my tank is full of asterina starfish but I have never seen any on the zoas. I know the solution for Asterina is to buy mated harlequin shrimp but I only have a 17 gallon and I don't want to have to keep a pair of them as suggested nor do I want to continue feeding starfish to them after they remove the Asterina starfish problem. My lfs does not do trade ins. I can give them my item if I want but they won't give me anything for it. I guess I could do that if there is no other way to rid my tank of these.

I also see some possible zoa pox beginning to appear. I am wondering if I should attempt the Furans-2 method, continue the dip with the seachem product, or try a different option. The problem with the Furan-2 method is I have no carbon filtration or any filtration except live rock and sand. i am worried I may have problems arise. Any suggestions. Thanks.

In regards to the nutrient issue, isn't it likely that my nutrients aren't low since I am constantly battling green hair algae?

I wish my camera took better photos to show what is going on. I'll do my best to post some halfway decent ones tomorrow. Thanks again for any suggestions.


New Member
It doesn't seem like anyone is a resident expert on this forum any more... Oh well, I am trying to figure things out. I am also on reef central and reef monkey but have not gotten any info from those either.


New Member

My colony of eagle eyes looks aweful and has been getting worse over the last week it looks as though the fungus is back or it could be decay because it is dying. They are dying off fast! I just spoke to an LFS and they recommended doing a freshwater dip for 5-10 minutes and cutting off all of the polyps that are dying/decaying to hopefully rid the colony of whatever the problem is and hope they come back. He also told me to lower my salinity in the tank to 1.020-.022 and lower my temp to 76 degrees.