Whole-house water filter cartridges
The cartridge sits in a canister, called the housing, on the main water line, often just after the main shutoff valve.
Find the right fit
- Model number. Start with the housing model number, on a label on the housing or its cap.
- Part number. Then the cartridge part number, length and width printed on the old cartridge. Common lengths are 10 and 20 inches, in a standard width or a wider one about 4.5 inches across. Note the micron rating too: it tells how fine a grit the cartridge stops.
- Two or more retailers. Look the model or part number up at two or more retailers. Buy the one listed as a fit for your model, and check the printed size or part number on the box matches.
What to look for
- Sediment cartridges catch sand and grit. Carbon cartridges help with taste and smell. Both words are printed on the box.
- A lower micron number catches finer particles but loads up sooner.
- Close the valves on each side of the housing before a swap, and keep a towel handy.
When to swap
As often as the cartridge or its box says.
Where to buy
Set a reminder for the next one in the Reminder Tool or the home hunt.