Dosing iodine when using activated charcoal

[Randy Holmes-Farley Verified Community Expert]

The "reefing urban legend" that carbon strongly binds iodine likely comes from a misunderstanding.

While carbon does adsorb elemental iodine quite well—a highly reactive form of iodine that's not found in reef tanks—this property was traditionally used to characterize carbon.

However, carbon is not very effective at binding iodide or iodate, which are the two main forms of iodine found in reef tanks.

Thank you, Christoph. :)

 

[immo]

Thank you, Christoph. :)

So I'm trying to understand better. I just had an ICP come back with iodine of like 733. Can I use GAC to reduce this number, or no?

 

[Randy Holmes-Farley Verified Community Expert]

So I'm trying to understand better. I just had an ICP come back with iodine of like 733. Can I use GAC to reduce this number, or no?

No. Neither of the two forms present in seawater (iodide and iodate) appreciably bind to GAC.