Choosing the right cartridge for the housing you already own.

Branded-Fit and Universal-Fit: what the names mean

LUXGEN sells its 10″ sediment and carbon cartridges in two fits. Branded-Fit is dimensioned for the housings used by the major purifier brands. Universal-Fit suits the standard 10″ housing used across the rest of the market and in most locally assembled purifiers.

The filter media is the same in both. Same 5 micron rating. Same wound polypropylene in the sediment cartridge, same coconut-shell carbon in the carbon cartridge. Same 125 PSI maximum pressure. Same rated life of up to 12 months. The only differences are the outside dimensions and how the ends seat in the housing. You are not buying a better filter with either. You are buying the one that fits.

Because the media is the same, the cheaper one is not a compromise. Universal-Fit carbon is ₹220 against ₹250 for Branded-Fit. If both happen to fit your housing — rare, but it happens with some generic bowls — buy Universal.

The six cartridges

The spun pack of two works out to about ₹130 a cartridge. It is a melt-blown, 2-layer gradient cartridge, which holds more silt before flow drops than a single-density one — a sensible choice on borewell water. The yarn-wound candle at ₹150 is the lightest of the six at 120 g.

Nine inch candle, ten inch housing: read this before ordering

This one causes the most returns. Pre-filter housings — the clear or white bowl on the wall ahead of the purifier — come with two cap designs. One has a plain cap and takes a full-length 10″ cartridge, which is held by the cap pressing down on it. The other has a female-thread cap: a threaded socket in the centre that the top of the candle screws into.

A 9″ yarn-wound candle like the LUX-YW-9 is made for the second type. It threads into the cap, and its shorter length leaves room for the thread. A 10″ spun cartridge does not fit that housing: it has no thread, and it is too long once the cap is on.

The reverse is also true. A 9″ candle in a plain-cap 10″ housing has nothing to hold it and sits loose.

1. Turn off the inlet and release pressure at the purifier.
2. Unscrew the bowl with the spanner.
3. Look inside the cap. A threaded socket in the centre means a 9″ candle: order LUX-YW-9. A plain cap means a 10″ cartridge: order LUX-SPN-10-2, or the Branded-Fit or Universal-Fit sediment cartridge that matches your housing.
4. Look at the cartridge you took out. Its length and its ends tell you the same thing.

When the housing itself is the problem

Sometimes the cartridge is fine and the bowl is not. A cracked bowl, a stripped thread, a housing so old that no cartridge seats properly. Replace the housing instead of fighting it. Two kits cover both cap types.

LUX-PFH-10 — Universal-Fit housing bowl kit with bowl, elbow, pipe, spanner and a 9″ 3-layer PP spun candle, ¼″ push-fit connections, 350 g. It ships with a 9″ candle, so it is the threaded-cap type. ₹499, down from ₹999.

LUX-PFK-2C — Universal-Fit housing bowl with two 10″ PP spun candles, elbows, spanner and pipe, 960 g. It takes 10″ cartridges and is rated for feed water up to 2000 ppm. ₹899, down from ₹1,199. Above 2000 ppm, read the TDS chart first.

Both kits and all six cartridges are in the full range; the four checks before ordering any spare are on the home page under choosing a cartridge. For how long each one lasts, see the filter change schedule.