SUPER high Iodine in ICP results

[Terence]

So I just got my second ICP back on my tank. The first one had Iodine level over 2000ug/l so I was super curious to see what the second one would show after doing five separate 17% water changes over a four week period between the tests. I had added no other elements to the tank in that period. My tank runs a CaRx and Denitrator as well as a huge patch of macro in the 200g 28sf sump.

My second test still showed over 2000. What is going on here!?

All my results are below - can someone (hopefully Randy) give me some insight or speculation on this and any other anomaly he may see in these results?

 

[Randy Holmes-Farley]

I've seen this a couple of times in other posts, and never knew if it was real or not, but with two on the same tank, it does sound real.

What kind of denitrator?
What salt?
What brand media for the reactor?

What do you feed?

Seaweeds have a lot of iodine. Do you feed a lot?

Any dosing even before the last sample?

 

[Tim2@Triton]

watching this thread. I have heard that nori can be a source

 

[Terence]

I've seen this a couple of times in other posts, and never knew if it was real or not, but with two on the same tank, it does sound real.

What kind of denitrator?
What salt?
What brand media for the reactor?

What do you feed?

Seaweeds have a lot of iodine. Do you feed a lot?

Any dosing even before the last sample?

I use the AquaMaxx denitrator with their (MarineDepot) media that came with it as well as a bit of TLF Reborn at the top mixed with their Calcium rubble.

I was using the anhydrous ATM Hot Salt for over a year. I just switched to Fritz (2-3 of the 5 water changes were with Fritz).

For the CaRx I use TLF Reborn with TLF ReMag mixed in.

I feed LRS Frozen (ReefFrenzy and Herbivore Frenzy), TLF Algae Flakes (shreaded mixed Nori), Spectrum pellets, Various ReefNutrition foods in small and infrequent (once or twice a week) quantities, and then I put about 2-4 sheets of nori in the tank a week. I was careful to sample the water first thing in the morning before any feeding and I had not fed any type of Nori for at least 36 hours.

I just think to get to those levels in 550-600g of water would be a crazy amount of Nori.

 

[Terence]

Oh, and I did not do any dosing of any kind of elements for many weeks before this sample.

 

[Terence]

Here is where it was five weeks earlier.

 

[Terence]

Also, you can see that I grow a ton of macro in my sump. This pic was this morning after harvesting a beach-ball sized amount out of my patch.

So, why is this not helping take up that iodine?

 

[Randy Holmes-Farley]

watching this thread. I have heard that nori can be a source

Nori is certainly a source, but it would take an incredible amount to get to this level of iodine. It contains very roughly 40 mg/kg.

An aquarium with 2 mg/l (like the OP) would need to add 50 grams of nori per liter of water. That's like 20 sheets per liter. Seems far fetched, even over time.

 

[Randy Holmes-Farley]

Also, you can see that I grow a ton of macro in my sump. This pic was this morning after harvesting a beach-ball sized amount out of my patch.


So, why is this not helping take up that iodine?

Maybe it is. Who knows where it is coming from and in what amounts.

 

[Terence]

Nori is certainly a source, but it would take an incredible amount to get to this level of iodine. It contains very roughly 40 mg/kg.

An aquarium with 2 mg/l (like the OP) would need to add 50 grams of nori per liter of water. That's like 20 sheets per liter. Seems far fetched, even over time.

I had thought that possibly last time a flake of Nori might have entered the sample - since I do feed that shredded Nori. But two tests in five weeks with 80% of the water changed makes me think something else has to be leaching it in, or (more likely IMO) there is a flaw in the test when levels of something else line up a certain way.

 

[ReeferBean]

Could it be possible that the measured iodine level is not accurate with the ICP test?

 

[greg 45]

Is it possibly a testing error on there end .
My only other question is do you have a Iodine test kit available to double check there results.

 

[Lasse]

@Randy Holmes-Farley

According to my high Si levels (more than 1000 ppm) I´m now sure they was real because my two last test still show high values. The concentration is going down slowly but last test show around 600 ppm Si

@Terence From the wild - its know that some macoalgae can produce rather much low-molecular-weight halocarbons like CH3I One example . I can´t say that this is the reason for the high Iodine readings but it could be one way to understand the readings

Sincerely Lasse

 

[litenyaup]

how is your tank doing? are there any ill effects from it being so high?

 

[Randy Holmes-Farley]

Could it be possible that the measured iodine level is not accurate with the ICP test?

Yes, but it is not a normal systematic error since 99% of people using the exact same service do not have such elevated levels.

 

[Randy Holmes-Farley]

From the wild - its know that some macoalgae can produce rather much low-molecular-weight halocarbons like CH3I One example . I can´t say that this is the reason for the high Iodine readings but it could be one way to understand the readings

yes, there's certainly no reason to assume it is iodide.

 

[Terence]

Now I am even more confused.

 

[andrew james]

Have you tested some freshly made water just to rule out your salt mix?

 

[Randy Holmes-Farley]

Now I am even more confused.

About what?

ICP detects just elements and never says anything about chemical forms. Iodine the element can be in many forms in a reef tank: iodide, iodate, organoiodine forms, etc.

This has more:


Chemistry And The Aquarium: Iodine in Marine Aquaria: Part I ? Advanced Aquarist | Aquarist Magazine and Blog
http://www.advancedaquarist.com/issues/mar2003/chem.htm

Chemistry And The Aquarium: Iodine In Reef Tanks 2: Effects On Macroalgae Growth ? Advanced Aquarist | Aquarist Magazine and Blog
http://www.advancedaquarist.com/issues/april2003/chem.htm

 

[Terence]

About what?

ICP detects just elements and never says anything about chemical forms. Iodine the element can be in many forms in a reef tank: iodide, iodate, organoiodine forms, etc.

This has more:


Chemistry And The Aquarium: Iodine in Marine Aquaria: Part I ? Advanced Aquarist | Aquarist Magazine and Blog
http://www.advancedaquarist.com/issues/mar2003/chem.htm

Chemistry And The Aquarium: Iodine In Reef Tanks 2: Effects On Macroalgae Growth ? Advanced Aquarist | Aquarist Magazine and Blog
http://www.advancedaquarist.com/issues/april2003/chem.htm

I have already read those and digested to the best of my ability.

What is the point of even measuring it if there is no meaning to the result? I do not care to know any information that is inconclusive or action cannot be taken on it.

And in terms of the Triton method, if in fact macro algae (a key component of the system) can throw off this test, what is the point in testing it (or paying attention to it) at all? The Triton recommendation from my results above was to do six 15% water changes over six weeks. And for Iodine, it told me "Your Iodine levels are too high. Check for possible contamination source. To help you in your search for the source of error, we have listed the most common sources of iodine (sorted in descending order of frequency):

1. Trace element overdose / contamination
2. Contaminated salts"

No where do they say that this could be a false reading from my macro algae.