Some of the limitations of RO system are mentioned as follows - Chlorine free water is required as RO feed for preventing membrane from spoiling, RO membranes are unable to filter out chlorine or other chemical pollutants. In a similar vein, they are unable to stop microbes or particles that are smaller than the membrane's hole sizes. Feed water quality should be maintained as per design specifications of the RO membrane. There is no one fit for all solution.