Don’t buy this · Water
Don't buy RO on low-TDS water
The verdict
If your supply is reliably below about 200 ppm, RO is solving a problem you do not have. It will discard two to four litres for every litre produced, cost ₹1,800 to ₹5,500 a year in consumables, and remove dissolved minerals that were not causing you any difficulty. On low-TDS municipal supply the actual risk is microbiological, and UV or UF addresses that directly — for less money, with no water wasted, and with far less to maintain.
When this does not apply to you
Placed here rather than at the end, because if one of these describes your situation then the rest of this page is the wrong advice and you should know that now.
Your supply is intermittent or mixed
Many Indian municipal supplies are blended with borewell water seasonally, and TDS can swing by hundreds of ppm across a year. A single low reading in December says little about May. Measure across seasons before ruling RO out.
You are on tanker supply, even at low TDS
Tanker source and handling are unverifiable and change delivery to delivery. Low TDS today does not predict tomorrow, and the microbiological risk is the larger issue anyway.
You have a specific contaminant that RO removes
Fluoride, nitrate, arsenic and uranium can all be present in water with unremarkable TDS. If a lab result shows one of them, RO is warranted regardless of the TDS reading.
Why you were told otherwise
Usually not because anyone lied to you. Almost every claim in this category is technically true and incomplete, which is a much more durable technique.
- RO carries the highest margin in the category, and it is the technology every brand advertises hardest.
- The TDS demonstration works at any reading — a salesman can show you 180 ppm and describe it as 'dissolved impurities' without saying anything untrue.
- 'RO+UV+UF+TDS controller' sounds more thorough than 'UV', and thoroughness is easier to sell than appropriateness.
- Nobody earns a commission on telling you that a ₹6,000 UV unit is enough.
What to do instead
A page that only says no is an opinion. This is the part that makes it useful.
- 1
Buy a UV purifier if your concern is microbiological
On low-TDS municipal supply, UV addresses the real risk. No water wasted, cheaper to buy, and the only consumable is an annual lamp.
Read more → - 2
Buy UF if power reliability is a problem
UF gives a physical barrier against bacteria and cysts with no electricity at all, which matters where supply is unreliable. It is weaker against viruses, so pair it with boiling where sewage ingress is plausible.
Read more → - 3
Measure TDS across a full year before deciding
A ₹300 meter and a monthly reading tells you whether your supply is genuinely stable. That is the single fact this decision turns on.
Read more →
Note
Frequently asked questions
Is UV enough for municipal water?
Does RO water waste matter if I have plenty of water?
Is RO water bad for health because it removes minerals?
Cost figures are indicative Indian market ranges for budgeting, last reviewed 2026-08-08. This page argues about the general case; the exceptions section above is where the specific case is dealt with, and it is written honestly rather than as a hedge.