Ok, I get that, but if you put enough chlorine in manually, then the cell wouldn't have to generate as much....or am I just not getting it? So if you started out with 5ppms, and your cell was just making free chlorine as needed, then wouldn't it make enough fc to keep the level up to 5? Or is that what you mean 30% - 45% is? As you can see I don't have a SWG.