RO, UV and UF are three different purification technologies. Each solves a different problem, which is why many purifiers combine them. The right choice depends mainly on your water source and its TDS.
Quick comparison
| RO | UV | UF | |
|---|---|---|---|
| Removes dissolved salts (TDS) | Yes | No | No |
| Kills / removes bacteria and viruses | Yes (membrane barrier) | Kills germs | Removes bacteria and cysts; not all viruses |
| Removes mud and turbidity | With pre-filters | No – needs clear water | Yes |
| Needs electricity | Yes | Yes | No |
| Wastes water | Yes (drain water) | No | No |
Step 1: Test your water TDS
Use a TDS meter on your tap water. Indian drinking water standard BIS IS 10500 sets the acceptable limit at 500 mg/L. Read more in what TDS is good for drinking water.
| Your water | Recommended purifier |
|---|---|
| TDS above 500 – borewell, tanker, hard water | RO (usually RO + UV or RO + UF) |
| TDS below 300 – municipal / corporation supply | UV + UF is often enough |
| Muddy / cloudy water | Pre-filter + UF or RO |
| Unsure or mixed sources | RO + UV + UF with a TDS controller |
When you need RO
If your water tastes salty, leaves white scaling on utensils, or has high TDS, only RO will reduce it. UV and UF do not remove dissolved salts, fluoride excess or heavy metals.
When UV or UF is enough
If your water already has low TDS and comes from a treated municipal supply, the main risk is germs. UV kills microorganisms and UF physically filters bacteria and cysts. Using RO on very low-TDS water removes minerals you do not need to remove and wastes water.
What about TDS controllers and mineral cartridges?
A TDS controller mixes a little filtered (non-RO) water back to keep some minerals. A mineral or alkaline cartridge adds minerals after the membrane. Both help when RO output TDS is very low.
Buying tips
- Check the storage capacity – 8–12 litres suits most families.
- Check the ongoing cost: filter and membrane replacement every 1–3 years.
- Prefer brands whose spare parts are easily available.
Browse domestic RO water purifiers.
Frequently asked questions
Is RO water safe to drink every day?
Yes, when the purifier is maintained and the output TDS is not extremely low. A mineral stage or TDS controller helps with taste.
Can UV purifiers remove TDS?
No. UV only kills germs; it does not reduce dissolved salts.
Which is best for borewell water?
RO (with UV or UF) is usually needed because borewell water often has high TDS.
Need help choosing the right part? Send a photo of your RO or its model name on WhatsApp (96252 23245) and we will tell you exactly what fits.
Need the right part for your RO?
Original filters, membranes and pumps at wholesale rates. Send us a photo of your RO – we will tell you exactly what fits.
