Quick Answer
For most Indian homes — especially those using borewell water or water with high TDS — an RO+UV+UF combination purifier is the safest and most practical choice. If you are on low-TDS municipal supply, a UV purifier alone may be sufficient and cheaper to run. Here is the full breakdown.
The Three Technologies Compared
| Type | What It Removes | Electricity Needed | Waste Water | Best For |
|---|---|---|---|---|
| RO | Dissolved salts, heavy metals (lead, arsenic), bacteria, viruses, fluoride, nitrates | Yes | Yes (2–3 litres per litre purified) | High TDS water, borewell, hard water areas |
| UV | Bacteria, viruses, cysts (kills microbes but leaves dissolved solids) | Yes | No | Low-TDS municipal supply with biological contamination risk |
| UF | Bacteria, cysts, sediment, suspended particles (does NOT remove dissolved chemicals or viruses) | No | No | Low-pollution sources, areas with frequent power cuts |
| RO+UV+UF | Everything above — dissolved solids, heavy metals, bacteria, viruses, cysts, sediment | Yes | Yes | Most Indian homes |
RO Purifiers — Who Should Choose This
Reverse Osmosis pushes water through a semi-permeable membrane under pressure. It removes dissolved solids down to 0.0001 microns — small enough to filter out lead, arsenic, fluoride, and nitrates that other technologies miss.
- Best when TDS (Total Dissolved Solids) is above 300 ppm — common with borewell water and groundwater in many Indian cities.
- The downside: RO wastes 2–3 litres of water for every litre it produces. Many newer models include a waste-water recycling feature that redirects this to a separate tap for floor cleaning or gardening.
- Also removes some beneficial minerals — look for models with a mineraliser or TDS controller if this concerns you.
UV Purifiers — Who Should Choose This
UV (Ultraviolet) purifiers pass water past a UV lamp that destroys the DNA of microorganisms, making them harmless. It does not filter out dissolved chemicals or heavy metals.
- Best for municipal tap water that is chemically treated but may carry biological contaminants.
- Only works on clear water — sediment blocks the UV light. A sediment pre-filter is recommended.
- No waste water and relatively low running cost (just the UV lamp, replaced every 8,000–12,000 hours).
UF Purifiers — Who Should Choose This
Ultrafiltration uses hollow-fibre membranes with pores around 0.01–0.1 microns — small enough to stop bacteria and cysts but not dissolved chemicals or viruses.
- Works without electricity, which makes it useful for areas with frequent power cuts or as a kitchen-counter gravity filter.
- Not suitable as the sole purification method in areas with chemical contamination or virus risk.
- Very low maintenance — the membrane can be backwashed and reused multiple times.
When to Choose a Combination Purifier
Most Indian homes — particularly in cities like Bengaluru, Delhi, Chennai, and Hyderabad — face water that has both biological contamination and high TDS or chemical content. A combination RO+UV+UF system handles all of these together:
- RO handles dissolved solids and heavy metals.
- UV provides a second pass to kill any remaining microbes.
- UF acts as a final polishing stage and also works as a backup if the RO membrane needs replacement.
Expect to pay ₹8,000–₹18,000 for a good combination purifier. Annual maintenance (membrane + filters + UV lamp) typically costs ₹2,000–₹4,000.
Browse RO Water Purifiers on Amazon India ↗
How to Know Your Water TDS
A TDS meter costs ₹150–₹400 online and gives you an instant reading from your tap. Use this as your starting point:
- Under 150 ppm: UV or UF is likely sufficient.
- 150–300 ppm: RO recommended, especially if there is any risk of chemical contamination.
- Above 300 ppm: RO+UV+UF combination is the right choice.
If you are upgrading your purifier, you can sell your old water purifier in Bangalore to recoup some of the cost. And if you already own a Kent RO, check out our Kent RO error codes guide for troubleshooting common issues.