Reverse osmosis (RO) is one of the most effective water purification methods available for home use. It works by pushing water through a very fine membrane that blocks the vast majority of dissolved and suspended contaminants.
What RO Removes (Up to 99%)
- Dissolved solids — Lead, arsenic, fluoride, chromium, nitrates, and other heavy metals
- Chemicals — Chlorine, chloramines, pesticides, herbicides, pharmaceuticals
- Microplastics — Studies show virtually all bottled water contains microplastics. RO systems filter these out.
- PFAS ("forever chemicals") — Per- and polyfluoroalkyl substances that are very difficult to remove by other methods
- Total Dissolved Solids (TDS) — Minerals, salts, and metals dissolved in your water
- Bacteria and viruses — The membrane pores are too small for most microorganisms to pass through
What About Minerals?
Because RO is so thorough, it also removes beneficial minerals like calcium and magnesium. That is why our ZIP and U1 systems include an alkaline post-filter that adds healthy minerals back into the water after purification. You get the purity of RO with the taste and health benefits of mineral-rich water.
How to Check if Your RO System Is Working
The easiest way is with a TDS meter. Test your tap water, then test the filtered water. A properly working RO system should reduce TDS by 85–99%. For example, if your tap water is 300 ppm, your RO water should read between 3–45 ppm (before the alkaline post-filter adds minerals back).
All RKIN reverse osmosis systems — the ZIP, U1, and Flash — use high-rejection RO membranes designed for reliable, long-lasting performance.