No announcement yet.

ICP testing for Iodine

  • Filter
  • Time
  • Show
Clear All
new posts

  • ICP testing for Iodine

    We use Seachem's Iodide in our 300g mixed reef system, dosing 15 ml every day. (A trusted expert at a Seachem retail dealer offered that dose as what he uses.) A recent ICP test by Fauna Marin reported 0.51 mg/L IODINE in our tank water. Fauna Marin reports the desired Iodine level of 0.055 - 0.08 mg/L.
    Does the fact that ICP tests measure the element iodine versus iodide impact how I should interpret the ICP test value?

    Our 2 1/2 year old system contains 30+ LPS corals, several shrimp, crabs, lots of snails, starfish, urchins and about 20 fish, with the some such as the Tangs being pretty big.

    Thank you for your advice.

  • #2
    Thanks for the post, NanJ0508!

    ICP analysis will only tell the level of an element (as you stated) it will not tell you what form that element is in, or what compound it may be a part of. So you don’t know if it’s bioavailable or in an undesirable form. I’ve seen instances where repeated water samples from a coral system were taken and sent to different labs and got back wildly different results; like 0.91 mg/L, 0.09 mg/L, 0.088 mg/L, 0.03 mg/L of iodine. All from the same exact tank with samples from the same time. It is extremely difficult to measure what species the I is in seawater, and again ICP has no way to discern what kind is in the water. So personally if it were me I wouldn’t pay too much mind to the iodine results from ICP. I will point out also that many macro algae have a lot of iodine, if they feed a lot (particularly seaweed like nori) then that could contribute also, although I wouldn’t expect it to be a lot at all.

    I hope this helps!


    • #3
      Yes, it does help. Nothing about this hobby is simple! :-)


      • #4
        Awesome! Happy to help! :)