The Key to Zoanthid Growth - Is it Iodine?

that Reef Guy · Nov 14, 2014

I was talking to somebody today who had a lot of nice Corals.

I was asking him what he thought good growth was.

I told him that I did not have good growth.

If I get One Polyp a Month on my Zoanthid Frags I told him that I consider that good growth for me.

He said to have good growth you need to get at least double the polyps every month.

I was shocked!

He told me to Dose Iodine and that Softies especially Zoanthids love it.

I have never Dosed Iodine before because I was told it is easy to overdose and also that it is dosed for SPS.

I have never heard of it being dosed for Zoanthids.

Do you guys Dose Iodine for your Zoanthids?

If so how much and how often do you dose?

How much extra growth do you get out of using it?

I am also told that Zoanthids like High Alkalinity (10) so I have already been raising my Alk for that.

Before it was 6-7 but now I test everyday and am keeping it over 8.

Then next month I will raise it over 9, then 10 the following month.

I do not want to shock the system by raising it too fast.

Here are my Parameters

Temperature 78
Salinity 1.025
PH 8.1
Ammonia 0
Nitrite 0
Nitrate 0
Alkalinity 8.5
Calcium 440
Magnesium 1600
Phosphate 0

It is a 29 Gallon Tank.

I use RO Water and do a 13.8% Water Change every week with Reef Crystals Salt.

I have two Power Heads (Koralia 750 and Koralia 1050) for Flow.

I Dose Seachem AquaVitro Fuel Twice a Week.

Do you guys have any other tips on how to increase my insanely slow growth for Zoanthids?

reefaddictionrx · Nov 14, 2014

Excellent question...

I find it very interesting how some tanks are set up for great growth of SPS and then have very little success with zoanthids. (this is my current tank situation... I have a few zoanthid colonies that are ok, others really seem to suffer through). But with Ca/Alk dosing, my SPS are all doing very well in the 120g display. And it isn't flow related. The zoas are in a 60g frag tank with T5 lighting.

Makes me want to try some iodine dosing again to see if it helps...

ygon · Nov 15, 2014

I have been dosing iodide for about 4 months now and I have seen a nice improvement in growth and polyp extension. I use an iodide I purchased from brs and dose once a week per the instructions on the container. I really recommend that you also get a test kit and monitor your dosing that way.

that Reef Guy · Nov 15, 2014

ygon said:
I have been dosing iodide for about 4 months now and I have seen a nice improvement in growth and polyp extension. I use an iodide I purchased from brs and dose once a week per the instructions on the container. I really recommend that you also get a test kit and monitor your dosing that way.

What test kit do you use to measure Iodine?

What is the Target Level that you want your Iodine Level to be?

joshporksandwich · Nov 16, 2014

I add iodine because there's traces of it in the ocean but i have not seen any difference with it or without. I get horrible growth compared to some friends and we do the same stuff. I say 1 a month or 5 a month if you keep it alive that's what matters.

Randy Holmes-Farley · Nov 16, 2014

I don't believe there is convincing evidence that any of the organisms we keep need iodine except for certain gorgonia which use it in a well known way.

Many of us dosed iodine for years and then stopped and saw no difference.

That said, while I have had some zoanthids over the years, I've never tried to track their growth rate with or without iodine. Iodine might help them grow faster, but I'm skeptical or this would have become common knowledge long ago.

To keep this in perspective, many people make several changes in their tanks, or things change over time without them knowing it, and they sometimes then attribute the result to one of the changes they made when it could just as easily have been other issues.

However, it would be a nice experiment if you started some iodine and compared the growth rate before dosing to afterwards. Iodine dosing, at least in a tank that is skimmed and has water changes, is unlikely to harm anything.

Then report back and let us know what happened.

that Reef Guy · Nov 16, 2014

joshporksandwic said:
I add iodine because there's traces of it in the ocean but i have not seen any difference with it or without. I get horrible growth compared to some friends and we do the same stuff. I say 1 a month or 5 a month if you keep it alive that's what matters.

Does your friend Zoanthids DOuble in Size Everyy Month?

What does he do to get the extra growth that you do not do?

joshporksandwich · Nov 16, 2014

that Reef Guy said:
Does your friend Zoanthids DOuble in Size Everyy Month?

What does he do to get the extra growth that you do not do?

You need to understand that every tank has its own personality. You will find some stuff will do better in your tank and some stuff not. You can do the exact same things I do and you will get different results. If you're on top of all your parameters everything should do good.

duke4130 · Nov 16, 2014

I did the iodine thing for a little while. I realized that I was already adding it when I dosed Fuel into the system. Like Josh said, everyone's system is different. I didn't see a big difference. The only time I really use iodine is when the zoas aren't looking to hot and I dip them in some water with a couple of drops of Lugols

ygon · Nov 16, 2014

that Reef Guy said:
What test kit do you use to measure Iodine?

What is the Target Level that you want your Iodine Level to be?

I use the Salifert iodine test. I simply test and make sure it is at or slightly below natural sea water. Iodide gets consumed pretty quickly so if you stop dosing you will return to untraceable levels within a week or two. Like everything else in our hobby there are differing opinions on the subject. I had zoas that were not growing or growing very slowly before i started dosing and now are all growing well for me. It could be a coincidence but at the end of the day we are just trying to replicate their natural environment and this is an element found in natural sea water that is often missing from our systems..

RKLion · Nov 16, 2014

duke4130 said:
I did the iodine thing for a little while. I realized that I was already adding it when I dosed Fuel into the system. Like Josh said, everyone's system is different. I didn't see a big difference. The only time I really use iodine is when the zoas aren't looking to hot and I dip them in some water with a couple of drops of Lugols

Then after you do that do they bounce back? Or do you see any difference after?...

RKLion · Nov 16, 2014

One thing I notice is when I dose Lugols the ORP goes up...

duke4130 · Nov 16, 2014

RKLion said:
Then after you do that do they bounce back? Or do you see any difference after?...

Yes sometime it works and others it doesn't. Best to use iodine when you frag as well

Randy Holmes-Farley · Nov 17, 2014

RKLion said:
One thing I notice is when I dose Lugols the ORP goes up...

Lugols contains I2, which is a fairly strong oxidizer, so that is presumably why the ORP rises (and why it is useful for killing bacteria and such in dips and wounds).

The oxidizing aspect is also why I recommend that folks who want to dose iodine do it with the naturally predominant forms of iodide or iodate, although I recognize that many people use Lugols.

Randy Holmes-Farley · Nov 17, 2014

FWIW, I discuss the various forms of iodine and what is known in the scientific literature to use it (at least as of when the articles were written a number of years ago).

The second article contains a study I did of whether two macroalgae were helped by iodine since algae is one of the main things known to take it up:

Chemistry And The Aquarium: Iodine in Marine Aquaria: Part I ? Advanced Aquarist | Aquarist Magazine and Blog

Chemistry And The Aquarium: Iodine In Reef Tanks 2: Effects On Macroalgae Growth ? Advanced Aquarist | Aquarist Magazine and Blog

joshporksandwich · Nov 17, 2014

Randy Holmes-Farley said:
FWIW, I discuss the various forms of iodine and what is known in the scientific literature to use it (at least as of when the articles were written a number of years ago).

The second article contains a study I did of whether two macroalgae were helped by iodine since algae is one of the main things known to take it up:

Chemistry And The Aquarium: Iodine in Marine Aquaria: Part I ? Advanced Aquarist | Aquarist Magazine and Blog

Chemistry And The Aquarium: Iodine In Reef Tanks 2: Effects On Macroalgae Growth ? Advanced Aquarist | Aquarist Magazine and Blog

Randy i have both of this algaes and on your tests some of the culerpa died. In my fuge I've noticed that culerpa does great on higher flow where cheato likes the low flow. How do you control the temp on each of the saucers used for the ttest? I don't know if you still have time to do this tests but would love to do some tests on zoas and different chemicals. What do you say?

Randy Holmes-Farley · Nov 17, 2014

The samples were all contained in the same water bath at 80 deg F, so temp didn't vary.

I didn't have flow around them, but they were small bits in open water, so I wouldn't have expected a big flow component, but that certainly could be an issue with growth rates.

I think some caulerpa died simply because the pieces ended up being too small and/or damaged by cutting off from a larger piece that they didn't make it.

Unfortunately, I don't have the time to run more tests like that at the moment.

FWIW, my refugia are fairly low flow and the caulerpa does fine, but I cannot compare to how it would do at higher flow. I haven't added any supplemental iodine in many years, and my recent Triton test showed 0.02 ppm total iodine, although I do not know what form that takes (iodide, iodate, organic forms, etc.).