GROHE BLUE PURE NEW Blue Pure is an innovative and save water system to meet the highest level of filtration with the new reverse osmosis technology. The multiple-stage water filtration system removes bacteria, viruses and up to 99 percent of total dissolved solids.Combined with the magnesium and zinc filter GROHE Blue is the first product on the market that adds essential minerals while delivering pure tasting filtered water. Separate inner water ways ensure that unfiltered and filtered water do not come into contact.