there are very few reasons to dose iodine, your water changes replenish it, it is a poison, too much and you wipe out your tank, I have a tank full of Xenia's and everyone says to dose iodine for them, but you don't, water changes is all 90% of reefers need to do, dosing anything just complicates the whole process and makes keeping parameters balanced a lot harder. Why are you dosing?