Yeah, it’s well documented in R2R threads that FWS increases iodine.Noted something interesting. Months ago my ICP test would show Iodine around 36. Started using the Hanna nitrite with Red Sea regent test. Found about 0.2 ml a day would keep it between 67-75. This month I started dosing the KZ FlatWormStop. After I started using it, the iodine level shot up to over 100+. Stopped dosing and it stays between 80-100. Only thing I can see that caused the change was the FlatWormStop.