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FAQs on Iodine Use, Supplements 2

Related Articles: Iodine in Marine Aquarium Systems by Marco Lichtenberger, Marine System Additives

Related FAQs:   Iodine 1, & FAQs on Iodine: Rationale/Use, Iodine Testing/Test Kits, Sources of Iodine/Supplements, Dosing, Interactions, Troubleshooting/Fixing, & General Supplements, Calcium

How and what they dose at the world's largest reef system (CAS, Steinhart Aq. 2012)

Re: Sailfin Tang Heavy Breathing, I2 poisoning       2/17/19
Hi Crew,
A much delayed update on this situation:
So I sent out my water for an ATI ICP-OES test. It came back mostly good, with one huge and one marginal out of balance parameter:
Iodine was just under 40,000 micrograms per liter, nearly 1000 times what it should be!!!!!

<?! Where did this I2 come from?>
Salinity was low - 29.76 PSU. I'm not sure this was a good measurement - I ordered pinpoint calibration solution, recalibrated my refractometer, and was still getting an SG of 1.025. Not sure why the large discrepancy.
<Mmm; well... specific gravity is NOT the same as salinity... i.e., you could have other dissolved solids that are raising the former that are not salts.>
I think it's safe to say the iodine concentration was the cause of death of my fish, as well as the decline of so many corals. I had been dosing iodine, without testing.... bad reef-keeper.
<Aye yi yi... What is my mantra here? "Never dose/add something you can't and don't measure".>
I had been dosing iodine for nearly a decade, in the same manner (automatic doser for the last couple of
years) without testing and without noticeable issues - I had been under the impression that iodine dosing was critical for crustaceans building their exoskeleton.
<Well; yes; but very little. Many, likely most folks get by with the little that comes in w/ new synthetic water changes, foods>
In the fall, I switched brands to the two little fishies iodine concentrate and adjusted my dosing accordingly (I don't recall which I was dosing before, may have been Kent). I'm not sure if something weird happened at that time, or it was just accumulating over a very long time.
Regardless, after more reading about iodine and the mixed information on the need to dose for a healthy reef, I've decided to discontinue dosing iodine altogether.
Now, to remedy the iodine issue, I started doing several large (30%) water changes over the course of a couple of weeks. My corals started to respond within a few days of the first water change. Still not doing great, but starting on the road to recovery. I had also gone out and bought a Red Sea iodine test kit. My first test was, of course, completely off the scale of the test kit, which only goes up to 0.09 ppm. I wasn't surprised, really, when after 4 or 5 water changes, my readings were still off the chart, since the starting concentration was so high. At this point, I sat back and considered the fact that it would take months of water changes to get the iodine under control. I finally decided to just do a 100% water change. No fish in the system, and all the other parameters were within reason, so
nothing to lose with replacing it all.
<Mmm; you might add a "pad" of PolyFilter or a bag of ChemiPure in your filter flow path. These will absorb the leaching/back I2 over time.>
Finally, after the 100% water change (my dining room was filled with buckets and bins, and I learned my total system volume is actually about 75 gallons....), I checked my iodine levels and.... still off the chart.
<Ah yes... see above>
Something seemed strange with how the test kit was functioning, since the reaction is supposed to take 10-15 minutes, but seemed to complete instantaneously. Lo and behold..... my reagents had expired 1 month BEFORE I bought the test kit. I wasn't pleased. I did send a note to the LFS to let them know of this issue. I expect they don't sell many of these test kits, and a couple of forum posts indicated the Red Sea iodine reagents expire very quickly. I decided that, since I had just replaced all (except for a couple of gallons in plumbing, etc) of my water, there was no way the iodine was at lethal levels. My coral had already started to really respond and open up, regain color etc. So I moved my two survivors (the clown and sailfin - who had survived a bout of "black ich" in quarantine - thanks general cure) back into the main display. They are now happily swimming around, and the sailfin is starting to mow down an infestation of grape caulerpa that has taken over since his eviction.
<Some good news>
It looks like I'm finally back on track. I'll likely never dose iodine again - just not worth the trouble. Certainly won't dose without testing again.
Once I go a week with everyone still happy, I'll set up the quarantine tank again and begin to repopulate the tank - it just looks so lonely with 2 fish in there.
Thanks for all your advice. Hopefully any future emails will be with happier questions - like which dwarf angel I should put in there (leaning towards flame or coral beauty, since I'll be moving in the next couple of years and don't want to put a potter's through that stress).
<Thank you for your report. You've likely helped MANY other people to come.
Bob Fenner>

Freshwater dipping new corals & coral frags    3/16/14
I have looked through Wet Web Media and have not been able to find a complete answer to why dipping corals and frags in freshwater (RO/DI) is not recommended.
<Too much stress; not worth it in trade-off of what one might get in terms of lessening pests, parasites. Some slightly lower spg (a thousandth or two) with the addition of iodide/ate, and possibly a simple sugar (glucose or such... a hexose or pentose) IS>
 I have seen statements that say to not do it on Wet Web Media, but I would like to know the science behind the why.
<How much? Have you considered the use of a reference librarian... help w/ a computer search bibliography? There's bits and pieces re these on WWM>
Thank you for your time!
<Welcome. Bob Fenner>

iodide dip/bath, for Scleractinians    7/11/12
Hello Bob,
I ran out of Seachem Iodine and LFS has no more so I picked up a bottle of Brightwell Aquatics Lugol's solution, upon reading I see that the concentration is 3750mg/oz 126,803 ppm (!!) and each drop will increase iodine by 1,7ppm / gallon. If I want to make a dip/bath for helping coral to recover (stopping RTN and STN) How many drops should I add to how much water? I don't want to overdose as it's a very high concentration.
thanks in advance :D
<Mmm, yes; and though I'm not a giant fan of this format of iodine and potassium iodide... as a supplement, it can/will work for this disinfectant purpose. IF this were a commercial setting, I'd not worry re much at all re actual dosing (in practice I/we really just "squirt it in the transit volume/acclimation container", likely w/ a bucket of freshwater (to lower spg, increase uptake), and a scoop of a simple (hexose) sugar, like glucose... For home hobbyists, I might do something similar, but a short time exposure to some elevated level of Lugol's won't be harmful... I'd up the dosage to 3-5 drops per gallon for a several minute bath. Bob Fenner>

Marco... would you consider penning an article for pay on Iodine/ide/ate use in marine systems?   1/14/10
Your article on HPO4 sets the voice, standard. What say you?
Bob F
<Thank you very much and no problem, will do. Marco.>
<Ah, good. BobF>

Iodate 1/14/10
Hello crew,
<Hi Laurie>
I've referred to your site many many times over the past years and thank you for the valuable information.
I have a mature, five-year old saltwater tank. I've just recently upgraded my lighting, enabling me to now support corals.
Since I have added the corals, I thought it would be wise to check on the iodide level, wondering if I'd need to increase iodide supplementation. (I was adding 5 ml Seachem Iodide on even days to my 110 gallon tank, which
resulted in .06 ppm iodide - perfect, right?)
<Yes... but I would add on a punctuated basis... perhaps once a week after your water change regimen>
I couldn't get a valid reading from my Seachem test kit, so I supposed that it had probably expired.
While shopping for a new kit, I ran across Salifert's version which tests for iodide, iodine, and iodate. I ordered this one, and ran my first test.
The good news is that I got the same .06 iodide reading, but the bad news (I think) is that I got an off-the-charts iodate reading (>.2 ppm).
<Happens... and one reason I encourage only periodic dosing of I2>
I've read and re-read the information provided with the test kit regarding iodide and iodate levels, but I can't seem to find a definitive answer on what a high iodate reading really means, and which of these elements (iodide, iodine, and iodate) our marine specimens actually use. Salifert's web site does not have any additional information.
<Mmm, the valence state of Iodine changes to extents with local chemistry, physical properties of the water; but often it is the initial preponderance of one or t'other that results in such tests>
There is one piece of interesting information in the test kit instructions, under Interferences:
"The presence of strong reducing substances
<Mmm, yes... ORP, RedOx Potential... alters the valence state...>
such as ascorbic acid will also give a false value. Some supplements contain ascorbic acid."
<Mmm... I would not have put this statement in a circular... No supplement has this much Vitamin C... This information is spurious, unnecessary>
More on this in a moment...
So, my question is, what do I really need to be testing (iodide or iodate) and is this high level of iodate toxic?
<Really not generally an issue... Unless one is "really pouring it in" in concentrated doses... Again, I would just do your "normal dosing" once a week. Am sorry to state that I/we/WWM has not produced a comprehensive set
of declarative statements (an article) re Iodine/ide/ate and its practical use. The collection of FAQs re can be accessed here: http://wetwebmedia.com/ioddosingf.htm
and the linked files above.>
I perform 10% water changes biweekly (sometimes 5% weekly) along with cleaning or changing the filter media (paper and carbon).
<The carbon will remove...>
I recently switched to Red Sea Pro salt, which greatly increased the magnesium level (~1200 ppm now; was ~900 before), but do add a small amount of mg and sr twice a week (Seachem Reef Advantage). I supplement with
Seachem Reef Plus (Amino Acids and Vitamins) twice a week.
<Good products and good to stay with one manufacturer's line>
BTW - the first ingredient listed is ascorbic acid. And, as mentioned, add 5 ml of Seachem Iodide every other day. I do not need to add calcium - that usually tests between 450 - 500 ppm.
<I'd let slip into the 300's ppm range>
pH is 8.4; carbonate hardness is 10 dKH.
All of the coral look really healthy. For example, Zoanthid polyps are all fully opened; xenia is growing very quickly and spreading up the live rock.
<Good. A much better guide/test than any colorimetric assay>
Thanks for your help. I'll be very interested in your thoughts about this.
Best regards,
Laurie O.
<Sorry to be so scant here. I am not trying to be disingenuous, but I want to post "something" to the general public that is simple, straight-forward, applicable... and w/o potential dire consequence. Bob Fenner>

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