Most people do not know what their water filter is called, which makes finding the right replacement cartridge unnecessarily hard. Find the picture that matches yours, and everything else follows from there.
Filter pitcher or dispenser
You have this if: you fill a jug and it drips through into the bottom half.
Removes: chlorine, taste and odour. Some models are also lead-rated.
Cartridge: every 1–2 months.
Runs at: the highest cost per litre of any type.
Pitcher guide
Faucet mount
You have this if: a small unit screws onto the end of your tap, usually with a lever to switch filtering on and off.
Removes: chlorine, taste, sediment. Some are lead-rated.
Cartridge: every 2–3 months.
Note: will not fit pull-out sprayer taps.
Compare types
Refrigerator cartridge
You have this if: your fridge dispenses water or makes ice, and a cylinder twists out from inside the compartment or the base grille.
Removes: chlorine, taste, often lead.
Cartridge: every 6 months.
Critical: order by part number, never by brand alone.
Find your part number
Under-sink carbon
You have this if: one or two cylinders are mounted inside the cabinet under your sink, often feeding a small separate tap.
Removes: chlorine, VOCs, lead and cysts when NSF 53 certified.
Cartridge: every 6–12 months.
Runs at: usually the best value over five years.
Under-sink systems
Reverse osmosis
You have this if: there are three or more housings under the sink plus a horizontal tank, and the filtered tap runs slowly.
Removes: the broadest range — nitrates, arsenic, fluoride, dissolved solids.
Cartridges: pre-filters 6–12 months, membrane 2–3 years.
Note: sends some water to drain.
RO guide
Shower filter
You have this if: a short housing sits between the shower arm and the head.
Removes: chlorine at the shower — the reason skin and hair often improve.
Cartridge: every 6 months.
Note: does nothing for drinking water.
Shower filters
Whole house
You have this if: large tanks sit on the main water line, usually in a basement or utility room.
Removes: chlorine and sediment at every tap and shower.
Cartridge: 3–12 months, or years for tank media.
Whole house guide
Still not sure?
Photograph the cartridge and read the number printed on the body — that identifies it faster than any description. If it is already out and unlabelled, the appliance model number will do it.
Send us a photo
Nothing fitted yet?
Start with what is actually in your water rather than with a product. Your municipality publishes the analysis free each year.
Buying guide
The single most useful habit. When you change a cartridge, photograph the old one before throwing it away. The part number is printed on the body, and it is far easier to read from a photo than to work out from your appliance model two years later.
Product photographs on this page are illustrative and show generic filter types, not specific brands or models. Some links are affiliate links; if you buy through them we may earn a commission at no extra cost to you.
