Home & Lifestyle buying guide
How to choose a water purifier
The right purifier depends on what is in your water. Test your supply first: high dissolved solids, microbes and chemical contaminants each need different technology. A purifier that removes more than you need adds cost, wastes water and may strip useful minerals.
Weighted criteria
What matters when choosing water purifiers
Weights add up to 100 and reflect how much each factor usually decides satisfaction. Change them to fit you in the scorecard.
Technology matched to your water
30%RO targets dissolved salts, UV and UF target microbes, activated carbon targets taste, odour and some chemicals.
How to check: Get a water test (TDS, hardness, microbes, and any local concern) and choose technology that addresses the actual problem.
Certification & standards
20%Independent testing against a recognised standard for the contaminants claimed.
How to check: Ask which standard the claims are tested to. In India, check for a valid BIS licence where the product category requires one.
Filter life & running cost
20%Replacement cartridges, membranes and service visits over several years.
How to check: Ask for the price and interval of each consumable and add them up over three to five years.
Water wastage
10%RO systems send part of the water to the drain.
How to check: Check the stated recovery or reject ratio and whether the waste water can be reused for cleaning.
Service network
10%Whether trained service is available where you live and how quickly.
How to check: Confirm service coverage for your postcode or PIN code before buying.
Capacity & flow
10%Storage tank size and purification rate for your household.
How to check: Estimate daily drinking and cooking water and compare it with the rated output.
Avoid
Red flags
- A free "TDS demo" used to push RO when your water does not need it.
- Claims of removing "100% of all contaminants".
- Mandatory annual maintenance contracts with no itemised parts list.
- No information on which standard the claims were tested against.
- Health or disease-cure claims about "alkaline" or "ionised" water.
Before you pay
Checklist
- Test your water or get your utility's water quality report.
- Pick the technology that fits the result.
- Total up filter and service costs for several years.
- Check water wastage for RO models.
- Confirm installation and service availability where you live.
Ask the seller
Questions to ask
- Which contaminants is this tested to remove, and against which standard?
- What does each replacement part cost, and how often is it needed?
- What is the reject water ratio?
- Is installation included, and what does the service plan cover?
After you buy
Warranty & returns
Units often carry a one year warranty; filters and membranes are consumables and are usually excluded.
- Read what the extended service plan actually replaces.
- Keep a log of filter changes in case of a dispute.
Common mistakes
Myths vs facts
Myth RO is always the best choice.
Fact RO is useful for high dissolved solids. For low-TDS supplies with microbial risk, UV or UF may be enough.
Myth Lower TDS always means safer water.
Fact TDS measures dissolved solids, not germs or many harmful chemicals. Very low TDS is not automatically healthier.
Where this comes from
Official sources
- US EPA ground water and drinking waterUS
- Bureau of Indian StandardsIN
- Food Safety and Standards Authority of IndiaIN
- National Consumer Helpline (India)IN
Criteria and weights are AltFTool's editorial judgement, not a statement by these bodies. This guide is general consumer information, not professional advice.
FAQ
Water Purifiers: common questions
Do I need a purifier if I have municipal water?
Not always. Check your local water quality report. Problems can arise from storage tanks or old pipes, so testing at the tap helps.
Does RO remove minerals?
Yes, it removes most dissolved minerals along with other dissolved solids. Some units add minerals back; check what is added and why.
How do I know when to change filters?
Follow the maker's schedule and any indicator, and change sooner if taste, smell or flow changes.
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