NEW Ultrafine Biostone Water Filter fits all our Jupiter water ionizers. This Biostone filter represents the state of the art in water filtration today. Hollow fiber filtration –the same technology used in kidney dialysis — removes the finest particles, down to 0.01 microns. This is the finest domestic filter available. We recommend this filter for well-water, where there are hyper-allergenic issues, and in all cases where there are concerns about contamination. <--Read More-->