Reverse osmosis — under-counter and whole-home
Reverse osmosis — under-counter and whole-home
Reverse osmosis forces water through a semipermeable membrane that removes a broad range of dissolved contaminants — including PFAS, nitrate, arsenic, lead, and dissolved solids — producing the highest-purity water of the common residential treatment technologies. An RO system is a multi-stage architecture with pretreatment (to protect the membrane) and post-treatment (to make the water fit its use), configured to the specific water and household. RO comes in two configurations: point-of-use (under-counter) treating one tap, and point-of-entry (whole-home) treating all household water. This article explains how RO works, what each configuration does, what to consider, and the factors that inform choosing between them.
