How often should you change a water filter jug cartridge?

How often should a jug cartridge be changed?

Start with the full name on the refill pack, rather than a rule such as “one filter a month”. A jug is the reusable vessel; the cartridge or media dose has its own service interval. Two jugs that look alike can use different filters, and a refillable shell still needs fresh media on schedule.

For the systems below, both the time limit and the rated volume matter. Use whichever comes first, and follow an earlier replacement instruction if water conditions or the supplied pack require it. These are stated maxima, not a promise that every household will get precisely that many litres before a change.

The table is limited to these named products. BRITA Classic, MicroDisc, ON TAP and multi-stage under-sink systems need their own instructions. Use our cartridge compatibility directory if you cannot identify the family before setting a reminder.

Why a busy household can need a change sooner

Include drinking water, tea, coffee, cooking and every bottle filled through the jug. The relevant figure is filtered water used each day, not the jug’s total advertised volume. Refilling a 2.4-litre jug does not prove you have filtered 2.4 litres because that figure can include the upper reservoir.

A simple check is rated litres divided by daily filtered use. Compare that result with the time limit. At two litres a day, a MAXTRA PRO would take 75 days to reach 150 litres, but its four-week maximum arrives first. At eight litres a day, 150 litres is reached in 18.75 days, so volume arrives first. There is no extra allowance because the calendar reminder has not finished.

For Evolve+ at four litres daily, 100 litres takes 25 days, sooner than its 30-day maximum. A busy kitchen can therefore use a six-pack faster than a “six-month supply” description suggests. Four weeks is also 28 days, which differs from most calendar months.

You do not need laboratory-level metering to improve on guessing. Record bottles and typical kettle fills for a few ordinary days, including a busy day, then use a realistic household estimate. The running-cost calculator can compare the two limits and show the budget effect using your own pack price.

Choose the replacement for the system you already own

MAXTRA PRO jugs and Flow

For a supported MAXTRA PRO vessel, Pure Performance is an everyday-purpose refill. A hard-water scale priority may point you to Limescale Expert, but changing purpose does not create a longer calendar allowance. Keep the same fitting record when discussing how long a cartridge has already been in use.

Aqua Optima Evolve+

Use Evolve+ limits when that is the actual installed cartridge, including in a supported other-brand jug. Compatibility does not transfer BRITA’s service rating to Aqua Optima media. If your jug needs a PerfectFit key, check the Evolve+ fitting guidance as well.

Refillable media systems

Aarke Pure uses fresh granules in a retained steel filter. PHOX Clean uses fresh media in its reusable cartridge system. Count complete refill doses rather than the number of shells or the weight of a bag. Keep their different maxima separate when stocking up.

Keep a fitting record that survives a reset or holiday

Write down the cartridge family, when it was fitted and the next scheduled change. A calendar reminder helps when a display fails or someone accidentally resets it. If several people fill the jug, agree who checks the record and who orders replacements; otherwise a working indicator can still be ignored.

A red light or missing Memo bars is a maintenance prompt, not a diagnosis of the water. Equally, a green light does not override a known early volume limit. Our Memo and Smart Light guide explains the different reset confirmations. Reset after the actual cartridge change, rather than after every wash.

Harder water can reduce useful service life, and the manufacturer’s instructions for your conditions take priority. Persistent slow filtering, damaged packaging or an unusual water change need their own checks; simply waiting for the planned date may not be appropriate. Appearance and taste cannot certify remaining treatment performance.

Cleaning the vessel does not restart the media’s life. Nor should an unused weekend or holiday be treated as an automatic pause in the original calendar limit. Read the holiday and restart guide for the different storage procedures. If the fitting age or condition is unknown, a fresh compatible refill gives you a clear starting record after cleaning the jug.

Keep unopened spares in their original packaging under the maker’s storage conditions. Plan your next order before the change is due, but do not overbuy an unidentified family because the unit price looks low. When the old filter is removed, use the UK recycling guide to check the current accepted route.

Common questions

Sources and further reading

• BRITA MAXTRA PRO international jug manual: English care and setup section
• BRITA cartridge preparation, storage and troubleshooting FAQ
• Aqua Optima Evolve+ filter specification
• Aarke Pure refill specification and comparison
• PHOX Clean refill specification