Thanks. Yes I do keep 50 PPM borax from the advice I have seen here. The reason I ask is that Watermaid recommends the Magnesium Sulfate, even though I don't have a Watermaid unit, My thinking is it would also apply to the American made SWG's. Can I start adding Magnesium Chloride even though I have regular Solar Salt, or would I need to dump the pool water and start over ?