I've never conducted reverse osmosis measuremtnts to see if fluorides added to drinking water are removed well. But remember the natural calcium fluoride I wouldn't worry much about, being 25 times less toxic than the artificial additives because they are accompanied with sufficient calcium. It seems that if one's water is at a basic pH like ours here is, about 8, that little free fluoride ion would exist for the silicofluoride additive, but I don't know for sure. If so, the osmosis procedure one would think would work pretty well.We just need some data. richard sauerheber