We might be on to something. When I increased my calcium and did the stain remover/seqeustrant I also got a milky pool for about a day, which cleared on it's own. Perhaps we did actually filter out the metals but needed the higher calcium hardness to do it. I did not notice such a severy drop in calcium harndess from what I remember, however. All I know is that I have been keeping my calcium between 350 to 400 ppm which, with my TA at 70 and my salt and baorates, gives me a calcium saturation index close to 0 (well within the +/-.3 range, actually close to -.1). When I has a lot of staining problems it was on the negative side and in the neighborhood of -.6. Not sure what might be going on here but, like I said, I have not used seqeustrant or ascorbic acid for a few years now and pool is staying white!