Dosing iodine?

[Doctorgori]

dosing it is a fine experiment in most tanks

I’ve followed Randy for a while, you definitely have to catch some subtleties in his (normal tone) writing…
note the word “Experiment”

I dose it and can see the difference but I under rather than overdose as it is easy to overdo and toxic at higher levels. I never dose according to guides like Red Sea i.e so much per amount of calcium.

I do similar, I have a bottle and admit to willy nilly dosing whenever I “feel” it’s needed… I’d be irresponsible to post any actual reasoning behind it …I have seen softies “perk up” after dosing Iodine when in decline, but admittedly nothing annotated , documented or measured..

TLDR : 100% dose iodine. It can’t really hurt in moderation but it can definitely help.

I don’t regularly dose it because I have no measurable, protocols or any scientific basis for determining the dosage amount…
I’m on the fence as I’m 100% certain Iodine reversed decline in some softies, esp xenia…but again, no documenting, no measuring, no metrics to assign any trends…
I can’t post any meaningful data besides gut feelings

 

[crazyfishmom]

I dose AFR and after an ICP my iodine levels were low. I had been seeing issues with hammers and torches bailing out during splits. I even made a thread about it. Just a short month after starting iodine dosing my torches and hammers have stopped bailing out during splits, the extensions for all of my LPS is amazing, and SPS that were growing slowly are taking off. In my tank it seems to have made a very significant difference.

+1 for dosing iodine here

 

[Pod_01]

There is a lot of research saying the corals use iodine to exchange gas and protect the zooxanthellae from the light.

I have to ask, do you have a link or name of the article to this research that shows iodine protects zooxanthellae from the light? Same for the gas exchange?

This statement on sun tanning ability for corals I only seen mentioned by a particular company/ individual but I have never located actual scholarly article on the subject.

I also seen similar claims for Fluoride and Zinc and the only supporting evidence was a link to a bottle of the element that I could purchase immediately…

Just to clarify I do dose Iodine and I think I see some improvement but I had SPS that STN regardless of the Iodine levels.

 

[lpramos]

Two things:
1. I recommend that you test anything you dose, such as Iodine. ICP is great, but expensive and has a time delay. I recommend this:

AN ACCURATE AND PRECISE METHOD FOR MEASURING IODINE

ABOUT THE ARTICLE: The article describes an accurate and precise method and it's development, for measuring the level of Iodine in a saltwater aquarium. It is a follow-up to an article written in 2021. The current article describes an improved...

www.reef2reef.com

I regularly use the test above right before sending in Total ICPs to Fauna Marin and get close correlations.
2. I have an auto-water change set up that runs 4 times a day. For elements such as Iodine, that deplete, I buffer my freshly mixed saltwater with a little extra. My tank water might be slowly depleting iodine, but it gets a fresh influx 4 times a day. So, the level stays pretty steady.

 

[rishma]

I dose a some iodine, but I really cannot comment on the benefits.

25 years ago I definitely convinced myself my soft corals looked better after dosing iodine. Xenia seemed to really react positively.

That bottle ran out, my tanks and methods changed and for at least 15 years and various tanks I didn’t dose any.

Then a last year I had a few ICP that showed my iodine was low but other than that everything was in range. So of course I decided I must dose some iodine.

I bought some, I dose it and the only thing that has changed is my ICP result. I notice no other change.

When this bottle runs out (which will be a very very long time from now) I cannot predict what I’ll do. I don’t detect it’s doing any harm or good, so I dose it because I have it.

 

[blecki]

Can guarantee reef crystals contains iodine because I sent freshly mixed water to triton a few months ago trying to rule out bad salt as a source of heavy metals (turned out to be a magnet on a frag rack rusting maybe?) so unless an unusual amount of iodine made it through my RODI it's from the salt.

Anyway to jump on the bandwagon I guess, I've dosed for a long time and only have anecdotal evidence but a) it depletes quickly and b) it seems absolutely essential for zoa growth but c) waterchanges are probably enough for most tanks.

 

[taricha]

I use Instant Ocean Reef Crystals salt, which I understand does not have iodine in it.

here's @rtparty useful comparison across many salt brands.
https://www.reef2reef.com/threads/the-ultimate-salt-test.949805/

IO and IO-RC have plenty of iodine - above target values of ~0.060ppm (IO/RC around 0.20 ppm in that test - and I also measure my IO to be between 0.10-0.20ppm) , however even people who use those salts find iodine depletes in their systems, so people may still supplement iodine, even if their salt is "above target value" for iodine.

So you could increase your water changes if they are very low and increase iodine input that way, but it still may not get you up to a typical target value.

my suspicion is that iodine levels may be more relevant to corals in how it affects the behavior of other elements - rather than Iodine being needed directly by corals.

 

[Randy Holmes-Farley]

my suspicion is that iodine levels may be more relevant to corals in how it affects the behavior of other elements - rather than Iodine being needed directly by corals.

That’s an interesting idea. For example, oxidation of iodide to other forms may cause a change in the form of other redox active elements, either by reacting with them or preventing other highly oxidizing species from gettin to them before reacting with iodide.


It may mean that the need for iodine also relates to the amount or type of other trace elements present, perhaps the light level, and other redox related issues.

 

[anhdreamer]

I never dosed but I was high in it. Weird Mayne cuz when I frag residual iodine left behind

 

[ZoWhat]

I keep a mixed reef, favored on softie side. I've never testede nor dosed iodine.....I would think that wc's with good salt would take care of any iodine/iodide depletion..... just my .2 cents....maybe some else has different thoughts

You should test if you dose Lugols iodine from Brightwell and others....

I was happily dosing 2-3 drops DAILY a couple years ago..... lost a ton of zoa colonies, like 500+ utterchaos', Rastas, too many to remember... it was like $2000 worth of zoas I grew out that I could have frag'ed and sold

ICP tests show my iodine was 70ppm where it needed to be around 1-2

I've since bought a Hanna iodine tested and any time it goes above 2ppm, I stop dosing for 4-5 days

Zoas absorb iodine quick.... but if you're not testing weekly you could be just piling on a bad situation.

My rule is to TEST anything I'm dosing once a week bc sometimes corals absorb a dosed element and sometimes they dont... changes week to week

 

[Randy Holmes-Farley]

I've since bought a Hanna iodine tested and any time it goes above 2ppm, I stop dosing for 4-5 days

FWIW, Hanna doesn't have an iodide or iodate checker that is of any use. If you detect I2 with it, there's a problem.

 

[jimk60]

That’s an interesting idea. For example, oxidation of iodide to other forms may cause a change in the form of other redox active elements, either by reacting with them or preventing other highly oxidizing species from gettin to them before reacting with iodide.


It may mean that the need for iodine also relates to the amount or type of other trace elements present, perhaps the light level, and other redox related issues.

It's my understanding that's it's better to dose iodide to raise iodine. Do you believe this to be true?

 

[Randy Holmes-Farley]

It's my understanding that's it's better to dose iodide to raise iodine. Do you believe this to be true?

Iodide and iodate are the primary forms in seawater (there is almost no i2), and I recommend dosing iodide. I do not recommend Lugols.

 

[Randy Holmes-Farley]

So iodine dosing is 100% necessary.

Well, that's obviously false since many folks keep fine reef tanks without dosing iodine.

 

[kilnakorr]

FWIW, Hanna doesn't have an iodide or iodate checker that is of any use. If you detect I2 with it, there's a problem.

I'm curious, so can you elaborate why this isn't possible?

 

[Randy Holmes-Farley]

I'm curious, so can you elaborate why this isn't possible?

OK, let's look at the Hanna.

Iodine Colorimeter – Checker® HC HI718

The HI718 Checker®HC (Handheld Colorimeter) provides a simple, accurate and cost effective way to measure iodine.

www.hannainst.com

I assume that is what folks mean.

The description:

The HI718 Checker® HC (Handheld Colorimeter) provides a simple, accurate and cost effective way to measure iodine. Introduced as an alternative to chlorine, iodine as a sanitizer decreases eye irritation in pools and saps and provides a more stable level of disinfection in adverse conditions. However, due to its toxic and corrosive properties, iodine is strictly monitored. Designed as a more accurate alternative to chemical test kits, the HI718 provides quick, accurate results in a few easy steps.

Thus, it is detecting I2, not I- or iodate. That alone is the death of it for a reef tank where I2 is not significant.

We know this with certainty because of the method used:

adaptation of the Standard Methods for the Examination of Water and Wastewater, 18th edition, DPD method

The DPD method detects I2 (iodine) not iodide or iodate:

DPD Method

Ozone Testing, Dissolved Ozone Testing, Rhoadazine D, indigo carmine, R-7511, R-7540,R-7518,R-7501,R-7512, K-7553,K-7513,I-2002, dissolved oxygen, dissolved o2,DPD, Indigo, K-7404, K-7433,I-2022,K-7423,I-2019,USEPA Methods for Chemical Analysis of Water and Wastes, USEPA, APHA Standards,Mercuric...

ozonesolutions.com

One of the most widely used testing methods for free and total chlorine makes use of something known as ‘DPD’ which stands for N,N Diethyl-1,4 Phenylenediamine Sulfate. The addition of DPD to water samples containing oxidizers such as free chlorine, bromine, ozone, iodine, chlorine dioxide and/or permanganate results in the formation of a reddish tint to the water whose intensity directly relates to the amount of oxidizer(s) present in the water sample.


Second problem:

Accuracy and resolution is 0.1 ppm. (Hanna tells us this).

Thus, natural levels of I at 0.06 ppm would be indistinguishable from zero.

 

[Tom1975]

I have a System with 6 different Tanks. All connected together. 1800 liters. I used all for Reef 100 -150 ml a day depending on kh, 10 ml A and K elements and had always low iodine and Iron on ICP. Since about 1year I use 5 Drops of Lugol solution and Iron. Since then both are in a good range. Iodine ist (almost) the only reason I do ICP Testing.

 

[jimk60]

OK, let's look at the Hanna.

Iodine Colorimeter – Checker® HC HI718

The HI718 Checker®HC (Handheld Colorimeter) provides a simple, accurate and cost effective way to measure iodine.

www.hannainst.com

I assume that is what folks mean.

The description:

The HI718 Checker® HC (Handheld Colorimeter) provides a simple, accurate and cost effective way to measure iodine. Introduced as an alternative to chlorine, iodine as a sanitizer decreases eye irritation in pools and saps and provides a more stable level of disinfection in adverse conditions. However, due to its toxic and corrosive properties, iodine is strictly monitored. Designed as a more accurate alternative to chemical test kits, the HI718 provides quick, accurate results in a few easy steps.

Thus, it is detecting I2, not I- or iodate. That alone is the death of it for a reef tank where I2 is not significant.

We know this with certainty because of the method used:

adaptation of the Standard Methods for the Examination of Water and Wastewater, 18th edition, DPD method

The DPD method detects I2 (iodine) not iodide or iodate:

DPD Method

Ozone Testing, Dissolved Ozone Testing, Rhoadazine D, indigo carmine, R-7511, R-7540,R-7518,R-7501,R-7512, K-7553,K-7513,I-2002, dissolved oxygen, dissolved o2,DPD, Indigo, K-7404, K-7433,I-2022,K-7423,I-2019,USEPA Methods for Chemical Analysis of Water and Wastes, USEPA, APHA Standards,Mercuric...

ozonesolutions.com

One of the most widely used testing methods for free and total chlorine makes use of something known as ‘DPD’ which stands for N,N Diethyl-1,4 Phenylenediamine Sulfate. The addition of DPD to water samples containing oxidizers such as free chlorine, bromine, ozone, iodine, chlorine dioxide and/or permanganate results in the formation of a reddish tint to the water whose intensity directly relates to the amount of oxidizer(s) present in the water sample.


Second problem:

Accuracy and resolution is 0.1 ppm. (Hanna tells us this).

Thus, natural levels of I at 0.06 ppm would be indistinguishable from zero.

Any test kit you would recommend. My understanding is that there aren't any affordable tests available with any accuracy. Therefore I dose at a low dose but don't test.

 

[bubbgee]

So iodine dosing is 100% necessary. I’ve been keeping tanks for 20+ years. I just started a new SPS tank in November 2023. Didn’t skimp. Took it slow. Started trying SPS in March when all of my levels were good and balanced. Literally all. Nitrate, Phosphate, Cal, ALK, Mag. Perfect and stable. Growing zoas, clams and everything great. Coraline growing like crazy. Every single SPS I put in would look good for a week. Look bad the next. And then start STNing. They would all die. Every single one.

In March I did a ICP. All levels came back good but Iodine. But someone here constantly says it isn’t necessary and immediately shuts it down with only their knowledge and not actual testing. So I ignored the iodine. It was low. But it wasn’t absurdly low. 9 when they call for 57.

Anyways. Fast forward to September and I’m talking to my buddy about it. I’ve literally asked everyone but he went to his friend and owner of Modern Aquatics in Illinois. He recommended dosing of Iodine and said I would see immediate changes in SPS health. Boy was he right. The few SPS I had gotten a few weeks before and I was sure were going to start losing flesh immediately started showing polyp extension. Within 10 days they started gaining color back. And now a month later they are showing growth tips. In 7 months of trying I couldn’t keep a single SPS alive. In all of my previous tanks I couldn’t get them to grow slow enough.

There is a lot of research saying the corals use iodine to exchange gas and protect the zooxanthellae from the light.

TLDR : 100% dose iodine. It can’t really hurt in moderation but it can definitely help.

What's your dosing regimen like? I have 85 gal total volume and I do 3 drops of Lugol every week.

 

[kilnakorr]

OK, let's look at the Hanna.

Iodine Colorimeter – Checker® HC HI718

The HI718 Checker®HC (Handheld Colorimeter) provides a simple, accurate and cost effective way to measure iodine.

www.hannainst.com

I assume that is what folks mean.

The description:

The HI718 Checker® HC (Handheld Colorimeter) provides a simple, accurate and cost effective way to measure iodine. Introduced as an alternative to chlorine, iodine as a sanitizer decreases eye irritation in pools and saps and provides a more stable level of disinfection in adverse conditions. However, due to its toxic and corrosive properties, iodine is strictly monitored. Designed as a more accurate alternative to chemical test kits, the HI718 provides quick, accurate results in a few easy steps.

Thus, it is detecting I2, not I- or iodate. That alone is the death of it for a reef tank where I2 is not significant.

We know this with certainty because of the method used:

adaptation of the Standard Methods for the Examination of Water and Wastewater, 18th edition, DPD method

The DPD method detects I2 (iodine) not iodide or iodate:

DPD Method

Ozone Testing, Dissolved Ozone Testing, Rhoadazine D, indigo carmine, R-7511, R-7540,R-7518,R-7501,R-7512, K-7553,K-7513,I-2002, dissolved oxygen, dissolved o2,DPD, Indigo, K-7404, K-7433,I-2022,K-7423,I-2019,USEPA Methods for Chemical Analysis of Water and Wastes, USEPA, APHA Standards,Mercuric...

ozonesolutions.com

One of the most widely used testing methods for free and total chlorine makes use of something known as ‘DPD’ which stands for N,N Diethyl-1,4 Phenylenediamine Sulfate. The addition of DPD to water samples containing oxidizers such as free chlorine, bromine, ozone, iodine, chlorine dioxide and/or permanganate results in the formation of a reddish tint to the water whose intensity directly relates to the amount of oxidizer(s) present in the water sample.


Second problem:

Accuracy and resolution is 0.1 ppm. (Hanna tells us this).

Thus, natural levels of I at 0.06 ppm would be indistinguishable from zero.

Thanks a lot Randy for the detailed explanation.