Seachem iodine test update - found a few threads on reef central from way back, saying the powder reagent needing mixing up, but the formulae had somehow been modified to correct this. Anyhow, mixed the powder after another test kit read zilch. And as if by magic, it worked. Just for info, my new saltwater is identical to my tank dosing 1 drop of Lugol's in 60 gallon SPS tank, daily. I suppose I better break out the potassium test kit.