How to Choose a Water Purifier in India (2026 Buying Guide)

Almost every bad purifier purchase in India traces back to skipping this step. A digital TDS meter costs about ₹300 and takes ten seconds to use, and the number it gives you determines which technology you need, how much you should spend, and what membrane rating to insist on.

Test at different times of year if you can. Supply that blends municipal and borewell water — normal in Bengaluru, Gurugram, Pune, Hyderabad and Chennai — can swing 300-500 ppm between monsoon and summer. Design for the worst reading.

If your area has any documented arsenic, fluoride or nitrate issue, also get a NABL-accredited lab test (₹1,500-3,000). A TDS meter cannot detect these, and they are exactly the contaminants that cause the most serious long-term harm.

• MATTERS — TDS controller: lets you retain minerals and adapt to seasonal input changes. Effectively mandatory on RO.
• MATTERS — Tank size: 5-6 L for two people, 7-8 L for three or four, 8-9 L for five or more, larger if your area has long water cuts.
• MATTERS — Water recovery: high-recovery designs halve reject water. Real money if you buy tankers.
• MATTERS — Tank hygiene: stainless steel or in-tank UV, particularly in humid coastal cities.
• MATTERS — Service reachability: the most under-weighted factor in the entire purchase.
• SOMETIMES — Hot water: genuinely changes your routine if you drink a lot of tea or coffee. Needs a proper child lock.
• SOMETIMES — Copper: pleasant, traditional, mild antimicrobial benefit on already-sterilised water. Buy for preference.
• MOSTLY MARKETING — Stage count: brands count sediment pads as stages. Read the actual technology list instead.
• MOSTLY MARKETING — Alkaline: raises pH, no solid clinical evidence of health benefit.
• MOSTLY MARKETING — 'e-boiling', 'zero waste RO': UV sterilisation and high-recovery RO respectively, both overstated.

This is the step that separates people who are happy with their purifier three years later from people who are not, and it takes five minutes.

Call the brand's customer care, give them your actual pin code, and ask two questions: is there a service technician covering this area, and how many days does a filter-change request typically take? Then ask for the AMC price in writing.

If they are vague, or the answer is more than two or three days, buy a different brand. The hardware differences between mainstream purifiers are small; the service differences are enormous. This is why KENT and Aquaguard remain the default recommendation in tier-3 towns even where their specifications are not the best on paper.

• Watch the technician measure input and output TDS, and write both numbers down. That is your baseline.
• Ask him to show you where the reject line goes, and arrange a bucket or drum if you want to reuse it.
• Confirm the TDS controller setting and what output TDS it produces. Adjust if output is below 40 ppm.
• Get the installation date, model number and serial number recorded, plus the warranty card filled in.
• Note the filter-change due dates in your phone calendar. Do not rely on the indicator light.