parts · Pan-India

RO Filter Replacement: Schedule, Prices & Priorities

Filter replacement is where water purifier ownership either costs you ₹3,000 a year or ₹8,000, and the difference is almost entirely about sequence rather than brand.

The rule that matters: cheap pre-filters protect the expensive membrane. The carbon pre-filter's job is to remove chlorine before it reaches the RO membrane, because chlorine chemically attacks the membrane's polyamide layer. Let the carbon filter exhaust and you are not merely losing filtration — you are actively destroying a ₹3,000 component with a ₹400 one.

So if money is tight, change pre-filters on schedule and stretch the membrane. Never the reverse.

Indicative charges

Filter	Replace every	Indicative price	Priority
Sediment filter (spun / candle)	6-12 months	₹150 - ₹400	Highest — protects everything downstream
Activated carbon pre-filter	6-12 months	₹250 - ₹600	Highest — prevents membrane oxidation
RO membrane (75-100 GPD)	12-24 months	₹1,200 - ₹3,500	On condition, not on calendar
UV lamp	12-18 months	₹500 - ₹1,500	High — fails silently
UF membrane	24-36 months	₹600 - ₹1,500	Medium
Post-carbon polisher	12 months	₹250 - ₹600	Medium — affects taste
Mineral / copper / alkaline cartridge	12 months	₹500 - ₹1,500	Low — functional, not protective

These are indicative market ranges across India, useful for sanity-checking a quote. Actual charges vary by city, brand and whether parts are genuine or third-party. Franchisee pricing for the same service differs meaningfully between cities — always get the quote in writing before work starts.

Genuine versus third-party filters

Third-party filters cost 30-60% less than brand-genuine parts, and for sediment and carbon cartridges from a reputable supplier they are usually a reasonable choice — these are commodity components with straightforward specifications.

The membrane is where we would not economise. A cheap membrane of unverifiable origin may have lower rejection than claimed, and you have no practical way to test that beyond measuring output TDS. Since the membrane is the component actually protecting you from dissolved contaminants, this is a poor place to save ₹800.

Also note that using non-genuine parts can void warranty on some models. Check before your first service if the unit is still covered.

Tip

After any membrane change, measure output TDS immediately and note it down. That single reading is your proof the new membrane performs as claimed — and your baseline for detecting decline later.

What a 'candle filter' actually is

A candle filter is a cylindrical sediment cartridge, named for its shape, and it appears both as the pre-filter inside RO units and as the sole filter element in cheap non-electric 'candle purifiers'.

The distinction matters. As a pre-filter in an RO system it is doing an appropriate job — removing sediment. As a standalone purifier, a ceramic candle removes sediment and some bacteria but no dissolved contaminants and no viruses reliably. It is not a substitute for UV, UF or RO, despite frequently being sold as a 'water purifier'.

Frequently asked questions

What is the price of an RO membrane in India?

₹1,200-₹3,500 for a standard domestic 75-100 GPD membrane, depending on brand and whether it is genuine or third-party. Industrial 4040 membranes run ₹6,000-₹14,000 each. We would advise using genuine or reputable membranes rather than the cheapest available, because the membrane is the component actually protecting you from dissolved contaminants and its performance is hard to verify.

Which RO filter should I change first if I cannot afford all of them?

The sediment and carbon pre-filters, without question. They cost ₹400-₹1,000 together and they protect the membrane — an exhausted carbon filter lets chlorine through, which chemically destroys a ₹3,000 membrane. Changing pre-filters while stretching the membrane is correct; the reverse is expensive.

Can I use third-party RO filters instead of genuine ones?

For sediment and carbon cartridges from a reputable supplier, generally yes — these are commodity parts and you will save 30-60%. For the RO membrane, prefer genuine or a well-known brand, since rejection performance is hard to verify and it is the component protecting you from dissolved contaminants. Note that non-genuine parts may void warranty on some models.

What is a candle filter in a water purifier?

A candle filter is a cylindrical sediment cartridge, named for its shape. Inside an RO purifier it serves as the pre-filter, removing sediment to protect the membrane. Sold as a standalone 'candle water purifier', a ceramic candle removes sediment and some bacteria but no dissolved contaminants and no viruses reliably — it is not equivalent to UV, UF or RO purification.