RO (Reverse Osmosis) removes dissolved salts, heavy metals and chemicals - essential when TDS is above 300 ppm.
UV (Ultraviolet) kills bacteria and viruses but does not remove dissolved impurities.
UF (Ultrafiltration) removes suspended particles, cysts and bacteria without electricity.
Why combine them?
Indian water often has both high TDS and microbial contamination. A multi-stage RO + UV + UF purifier covers both, and an alkaline/mineral cartridge restores taste and essential minerals.