Iodine eerily stable and low.

[pudge]

Running a 180 mixed reef for about 16 months.

I've been sending regular ICP tests to keep an eye on trace elements (for purposes of this thread I'll assume this is a good idea).

For the past 6 months over 3 ICP tests the iodine level has returned at 20-25 micrograms/L and ATI tells me it should be about 65. I have been dutifully replacing and more recently have been doing 3x weekly dosing with increasing amounts guided by the replacement amount. Despite increasing the dose over 3 intervals the result is the same.

All of my other trace and major elements are replaceable and respond as expected but iodine remains stubbornly low (critically low by ATI definition).

The corals look good. No problems with color or growth or polyp extension. My current project is growing acros and other than a few sensitive Tenuis this has gone very well.

Possible sources of iodine sink:
Chaeto refugium
Activated carbon
Coral growth and increased demand.

Over this same period I have also intentionally increased my nitrate and phosphate from 1-2/0.02 to 8-10/.06. Corals have responded well to this change and this could be contributing to increased iodine uptake but I am not a chemist.

Happy to provide other specifics if anyone thinks they would be useful. Thanks for any help or suggestions. Do I just keep increasing the dose? I have an unused dose head I could set up a daily dose.

 

[Randy Holmes-Farley Verified Community Expert]

Iodine is rapidly taken up by algae of all types. Whether it is beneficial for them or anything else in the tank is, IMO, an open question. But dosing more as an experiment is a fine plan.

How much of what form of iodine are you dosing now?

 

[pudge]

Iodine is rapidly taken up by algae of all types. Whether it is beneficial for them or anything else in the tank is, IMO, an open question. But dosing more as an experiment is a fine plan.

How much of what form of iodine are you dosing now?

Thanks,
Dosing 1.2 mL of the 100 mL bottle ATI iodine supplement per week in 3 doses (0.4 mL). I cannot find the 100 mL bottle anymore but it has the same total as the 1000 mL bottle so 10X concentration. 12,000 micrograms per week if my math is accurate. I have a large sump, so 200 gallons of total water is a very good estimate of system size.

 

[Randy Holmes-Farley Verified Community Expert]

Using your numbers, you are dosing about 1/4 of the natural value over that week. Doubling or tripling that dose seems like a fine experiment to me. :)

 

[pudge]

Using your numbers, you are dosing about 1/4 of the natural value over that week. Doubling or tripling that dose seems like a fine experiment to me. :)

Thank you,
I will give that a try. Probably double first to approach the correct dose with caution.

 

[Randy Holmes-Farley Verified Community Expert]

Ok, let us know if you see any tank changes. :)

 

[slingfox]

My ATI ICP-MS also shows critically low iodine at 24 micrograms/L. I am dosing some iodine every day by hand. I will soon switch to dosing Captiv8 Isol8 MT which is a multi-trace supplement since I travel. I doubt this will change much but I have a spare doser and all these traces around so may as well use them

 

[pudge]

I will probably set up a dose head for this I am not currently using. I have the 1000mL bottle of ATI iodine supplement which will be a 10x volume for the same iodine dose. That will be 24 mL per week. Roughly 3.5 mL per day. I asked ATI directly and got the response that that could be diluted with RODI H2O. So my plan is to dilute 10x again and dose 35 mL per day. I'll be sending more ICPs.

This hobby is an addiction. Send help!

Thank you.