How Often Should You Change a Water Filter Jug Cartridge?

General buying advice. Always check current specifications, prices and reviews with the retailer before you buy.

A filter cartridge does not last forever, and leaving an old one in can make the water taste worse. Here is how to work out when to change yours.

Follow the maker's guidance

The best guide is the instructions that came with your jug and cartridges, because different filters are made differently. Most give a time limit, a volume limit, or both, and say to change the cartridge when you reach whichever comes first.

Time and volume

Cartridges are usually designed to last about a set number of weeks or a set number of litres. A household that filters a lot of water will reach the volume limit sooner, so do not rely on the calendar alone.

Hard water and heavy use

In hard-water areas, a cartridge may reach the end of its life sooner because it is working harder on the minerals that cause limescale. If your jug has an electronic indicator, it can help you keep track.

Signs it is time

If the water starts to taste or smell different, the flow slows down a lot, or the indicator tells you to change it, replace the cartridge. A jug that has been left unused for a long time may also need a fresh cartridge.

Fitting a new cartridge

Follow the instructions for preparing a new cartridge, which usually include soaking or flushing it before first use. If you have been away for some time, empty the jug and refresh the water and filter as the manufacturer advises.

Keep the jug clean

Wash the jug and lid regularly with warm soapy water and rinse well. Keeping filtered water in the fridge and using it within the time the maker suggests helps keep it fresh.