Testing Iodine

Max1 · 2026-07-16T01:48:24-0400

Hi, I have a mixed reef tank that I know has low iodine from an ICP test. I thoght this would be an easy solution, I would buy iodine to dose, and a tester to check levels without needing an ICP test to follow up. I bought Red Sea Iodine+ to dose, and also the Hanna Iodine checker. Only after using the checker is the issue clear that the level I am aiming for are 0.06ppm Iodine, and the resolution of the Hanna Iodine checker are 0.1ppm, meaning that for all my tests it will either show 0.1 or 0.0. So for all tests have shown 0.0.

Does anyone else test the iodine in water?
Is this hanna checker pointless as for me to show a reading on the checker, I would need to have higher iodine in the tank than I want.
How do I solve this problem? I am guessing I need to get another tester, but unsure what type or brand.
Thanks

Dan_P · 2026-07-16T04:36:20-0400

Max1 said:
Hi, I have a mixed reef tank that I know has low iodine from an ICP test. I thoght this would be an easy solution, I would buy iodine to dose, and a tester to check levels without needing an ICP test to follow up. I bought Red Sea Iodine+ to dose, and also the Hanna Iodine checker. Only after using the checker is the issue clear that the level I am aiming for are 0.06ppm Iodine, and the resolution of the Hanna Iodine checker are 0.1ppm, meaning that for all my tests it will either show 0.1 or 0.0. So for all tests have shown 0.0.

Does anyone else test the iodine in water?
Is this hanna checker pointless as for me to show a reading on the checker, I would need to have higher iodine in the tank than I want.
How do I solve this problem? I am guessing I need to get another tester, but unsure what type or brand.
Thanks

Try this

Thread 'AN ACCURATE AND PRECISE METHOD FOR MEASURING IODINE'

Jan 25, 2023

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 method but using the same basic ideas as the 2021 method. The details of the method development are included for those who might be interested. It is an informative example on how methods development can be challenging. That being said if you are just interested in the "Bottom Line" you can skip to Section VII "THE PROCEDURE". This is where the...