A Zoa Conundrum...

[ReefBridge]

Ok Zoa gurus, I am perplexed. I've had my tank up for 6 months now, the Zoas were doing great until about two weeks ago. I haven't added any new fish or coral in about a month. All other corals are doing well, including acros, montis, duncans, acans, hammers and about 6 other zoa colonies. I am having issues with a couple of my zoa colonies only partially opening, and I'm not sure why. I have staked out my aquarium in the middle of many nights to shine flashlights and catch the culprits to no avail.

I originally thought it was water parameters, but they all checked out:
Red Sea Reefer 250
Ammonia: 0
Nitrate: 2ppm
Phosphate: 0.1 ppm
Alk: 10 dKh
Calcium: 450ppm
Magnesium 1415ppm

I have looked for zoa pox, spiders, nudibranches. I even watched the amphipods. I either can't discern what they are, (which I doubt), or it's not them. I would like to dip them, but they are attached to the rock now and I don't want to have to damage them so that I can do a dip. See pictures. The red monster mash zoas don't appear to be having any issues other than not opening. The orange (anyone know the ID?) zoas have a white worm living in their rock. It moves around at night from it's hole, picking at things like a peanut worm. I'm not sure if this is the problem or not.

Please let me know if you see anything I missed. Also, I'm having an issue with a lot of particulates in the water lately. That may be an issue, but I would expect it in all of my zoa colonies.

THANK YOU ALL!

 

[P-Dub]

I have found I am having a similar problem along with slow to no growth with some colonies. So, watching this one as well.

 

[jeffchapok]

My first inclination is that your nitrates are a little low. I know you are at the "recommended" levels, but zoas are soft corals and softies like a little bit dirtier water.

 

[Sticker shock]

I was having trouble with zoas for a while. Some did ok for a while and even spread a bit. Others just never did much of anything and even melted away. I started dosing just a small amount of iodine weekly and I have noticed a huge difference. Currently, I'm using lugols but am considering a switch to an iodide solution since I've read its safer to dose.

 

[ReefBridge]

I was having trouble with zoas for a while. Some did ok for a while and even spread a bit. Others just never did much of anything and even melted away. I started dosing just a small amount of iodine weekly and I have noticed a huge difference. Currently, I'm using lugols but am considering a switch to an iodide solution since I've read its safer to dose.

Thank you for the reply! I will definitely look into that. Do you know if there are any adverse effects to other species of coral?

 

[Sticker shock]

Thank you for the reply! I will definitely look into that. Do you know if there are any adverse effects to other species of coral?

Overdosing can be lethal to anything in the tank, which is why I'm considering an iodide supplement. To my knowledge there really isn't a good test for iodine so I'm only dosing 3 or 4 drops a week in my 75 gallon (which seems to be on the lower side of what most are dosing). I haven't had any issues on any inhabitants SPS, LPS, softies and anemones.

 

[Andreas' Reef]

Your nitrates should a bit higher for them to open up

 

[Reef and Dive]

I like to keep maximum Mg around 1300. Some entire colonies melt with higher values. Not saying that is the cause of the problem.

 

[littlebigreef]

Overdosing can be lethal to anything in the tank, which is why I'm considering an iodide supplement. To my knowledge there really isn't a good test for iodine so I'm only dosing 3 or 4 drops a week in my 75 gallon (which seems to be on the lower side of what most are dosing). I haven't had any issues on any inhabitants SPS, LPS, softies and anemones.

While it is easy to overdose lugol's it's simply a more concentrated form of iodine. If you move to another product you're basically just paying more of a diluted product. Your 3-4 drops a week sound about right. I generally dose 3-4 drops a 2x a week in my system (340 gals) which is zoa dominant. Naturally it's good to experiment and find a product you're happy with.

As to the OP, as mentioned zoas do like aquarium with slightly elevated nitrates and phosphates. I generally do about 4 cubes of frozen a night (for the fish) and then 3-4 table spoons of reefroids (broadcasted) in my 125/sump/fuge where I keep most of my colonies. That's a lot of fish poop and roids to keep the zoas fed and happy. You'd mentioned your aquarium was about 6 months old, it likely still has a little more maturing to do. If you're not currently, I'd suggest spot feeding your colonies to make sure they're getting enough food.

From your pics I don't see anything glaring issue/disease/nuisance algae etc that would cause me concern.

Two other items to consider, I'm a little further north than you and once winter finally set in I was having an issue with my zoas. As it turns out a heater was getting too hot when it turned on at night (I use 3 - 300 watt eheims). Took me a while to figure it out since the heater was only turning on at night. If possible it might be worth dummy checking. Zoa are also susceptible to alk swings. In order to maintain a 10dkh and 450 calc I'd assume you're dosing at least a 2-part. Might be worth while checking your alk in the evening and again in the morning over a few days to see how much is being used between dosing. One other consideration with dosing, while I swear by B Ionic I have gotten a 1gal sized bottle of alk that essentially had a 'hot spot.' While everything was perfectly dissolved something was amiss with the concentration and it caused the alk to skyrocket with every dosing. I've hear of people having similar issues with salt.

 

[Justin Aretz]

Iodide supplementation is arguably important. Rubidium is another element that I would suggest maintaining. Anecdotal evidence supports this - but far from proven.

Worth sending out an ICP test to get a check-in with your true parameters. 3 or 4 ICP tests and you'll be able to lock in on exactly how much iodine your tank consumes daily. I was dosing 45ml daily to maintain NSW levels in an 80 gallon mixed reef, for reference. Noteworthy that I was also running a large ball of chaeto, which will utilize iodide/iodine as well.

 

[sfin52]

I was having issues with a few things. One thing that seemed to help was an amino supplement. I love aquaforrest and seachem fuel. Thats helped me.

 

[FloridaMicroReef]

I call that characteristic half open - half closed = "squinting from a lack of iodide / iodine".

I think you guys nailed it!

I had an unusual loss of my zoas. 2 of the 3 zoas clusters in my 3 gallon pico reefjar just up and started slowly shrinking. (During this time I also noticed my GSP declining in health with only half the polyps coming out).

After weeks of shrinkage down to stubs, I started dosing Kent's Iodide to provide the zoas with iodine in a form they can easily use. I manually add drops of iodide on a daily basis. I can give you the ratio later if you want it.

The shrinkage stopped, stabilized, and just today the zoa polyps have started reopening and growing! Saved from the brink. Plus my GSP looks healthier now too!

In my pico tank, there is a third large cluster of zoas, and a SUPER huge colony of Green Implosion Palys. I believe all these zoas and palys love iodide / iodine and were sucking it out of the tank water. The 2 smallest clusters could not compete.

 

[FloridaMicroReef]

Personally, I never tested for Iodine, so I never scientifically confirmed I had a problem.

First off, I have a super small tank = 3 gallon bowl. Reefbowls and Reefjars like that just do large 100% - 66% water changes weekly. So never really bother testing for anything EVER, since every week so much water is changed. Plus, I add a few drops of "Tropic Marin - All For Reef" - so I did not possibly think that there was an Iodine / Iodide deficiency.

Then I stumbled across numerous people who said, that soft corals, and zoas (especially) use Iodine / Iodide supplements specifically for zoa health.

Somehow Zoas need the Iodide / Iodine to process the energy their zooxanthellae make in their polyps. When the Zoa has light. . . without enough Iodide it's almost like the zooxanthellae are over producing energy for the Zoa. . . therefore the zoa polyp squints or closes to limit the light getting to the zooxanthellae.

But with its metabolism all out of whack it withers and dies.

It's possible this could be happening in your tank.

Again this is a total guess.

Kent's Iodide is only like $7-$10 so worth taking a chance. Plus, even if it doesn't work. . . adding it as a trace element long term will probably help all the soft corals you might have in your tank, even if the zoas die.

But hopefully you can save them.

You want to dose Iodide. Iodide is Iodine in a safe form that the coral can easily use. Apparently, dumping in pure Iodine could be more dangerous.

The instructions say the "best method" is 8 drops of Kent's Iodide per 50 gallons each day. The bottle does not come with an eyedropper, so you'll need to buy one. I went straight to this MAX daily dose ratio. (but for a 3-gallon tank I use WAY less than 8 drops).

I should also tell you, that I'm also adding Brightwell Aquatics "Coral Amino" Acid because it was said to be a SUPER easy form of Food that corals can use to repair their bodies and regrow when ill.

So I agree with sfin52

I went straight to max daily dose on that also:

5ml per 50 gallons added daily. ( I drop that in the top of the tank water to broadcast feed, I don't bother target squirting the zoas with the Amino Acid.)

Good Luck!

This just worked for me. I don't want a "I have a hammer = everything is a nail" type situation. But the great thing is that both the Iodide and Coral Amino are cheap and useful long term so your money wont be wasted. And I enjoy adding the drops daily. It's as fun as feeding the tank.

 

[ReefBridge]

Ok, I’m dosing SeaChem Potassium Iodide... I don’t have any way of testing it though. Is it possible to overdose this stuff since it’s iodide and not iodine?

 

[Sticker shock]

I’d suspect you’d be ok by following the indications on the bottle. But you can overdose anything in a reef. Better to start slow than run into an issue. But I should add that I do not know what else is in the Seachem mixture.

 

[blasterman]

Iodine does impressive things for softies and LPS acting on ability of large polyp tissue to absorb light. Its typically replenished via water changes or heavy feeding of non processed food which is why most aquarist don't dose it and have great tanks. As I understand it's actually an unintentional contaminant in commercial salt mixes.

It's metabolized quite quickly in healthy tanks and even faster if you have a fuge. Darn near impossible to over dose. I add two drops bi weekly in a 20 gal of lugols.

Only negative is it can cause SPS to brown out a bit forcing you to turn up your lights. I would not bother with iodine in an SPS dominant tank for that reason. It can also exaseberate existing algae problem and increase diatoms on your glass.

One concern I have is the potassium in potassium Iodine could keep building up. Randy might have some comments on that.

 

[HuduVudu]

Not sure I should be suggesting this because zoas IMO are complete weeds, so here goes. Those don't look like they have enough light.

 

[FloridaMicroReef]

Ok, I’m dosing SeaChem Potassium Iodide... I don’t have any way of testing it though. Is it possible to overdose this stuff since it’s iodide and not iodine?

My understanding is that Iodide is a safer form of Iodine, than straight pure Iodine. Therefore harder to overdose, less likely to cause negative effects. But the "Potassium" part??? I'm not sure. Reef chemistry and polyp physiology is not my specialty.

I know for my own zoas, a 16 polyp colony was doing real bad. Way worse than Reef Bridge's photos. After immediately starting to dose Kent's Iodide at 8 drops daily per 50 gallons. . . . the polyp loss stopped. It looked damaged and sick for a while. November 9th, I started dosing. It wasn't till December 5th that the first polyp was certain to be open again and healing. Now 3 days later there are about 5 polyps that look like they are opening and will survive.

But I also do weekly water changes, so harder for an overdose to build up over time.

 

[GoReefin]

May want to check for these guys too. Had one come in on a frag from the LFS. Always fresh water dip before adding your zooanthids

 

[ReefBridge]

Not sure I should be suggesting this because zoas IMO are complete weeds, so here goes. Those don't look like they have enough light.

I'm doing the iodide bit now and I'm 4 days in. If I don't see improvements, I'll start looking towards the light. I did take one of my frags that isn't doing well and put him up near some of my SPS. If he does well there, then my lighting is probably too low and my SPS probably need more light as well.