UV purification uses ultraviolet light inside a small chamber. As water flows past a UV lamp, the light acts on microorganisms such as bacteria and viruses, so that they cannot multiply.
What UV does — and doesn’t do
- UV is used to treat microorganisms; it does not add any chemicals to the water.
- UV does not remove dissolved salts, so it does not change TDS. That is why it is often combined with RO.
- UV works best on clear water, which is why it comes after the filtration stages.
Why combine RO and UV?
RO helps reduce dissolved impurities, and UV adds a further purification stage. Using both in one system covers more of the common water-quality concerns than either stage alone.