Most filter jugs need a fresh cartridge every 4 weeks, yet many UK households stretch them to 3 months, letting limescale, chlorine, and PFAS slip through unchecked. Whether you use a Brita Marella, an Aqua Optima Liscia, or a Waterdrop jug, the right replacement cartridge costs as little as £2 per month and makes a genuine difference to taste and appliance longevity.
What to look for
01Replacement frequency and filter lifespan
Most manufacturers recommend changing your cartridge every 4 weeks or after filtering 100–150 litres, whichever comes first. In practice, a 2.5L jug refilled three times a day hits 100 litres in roughly 13 days, so hard-water areas in London, the South East, and the East Midlands may need changes even more often. Leaving a cartridge in too long does not just reduce filtration performance; it can allow bacteria to accumulate in the saturated media. Brita's digital LTI (Lid Timer Indicator) on the Marella XL takes the guesswork out by counting down automatically. If your jug lacks a timer, mark the change date on a piece of tape stuck to the base. Buying in multipacks, such as a 6-pack or 12-pack, cuts the per-cartridge cost significantly and means you always have a spare to hand.
02Cartridge compatibility across jug brands
Not all cartridges fit all jugs, and using the wrong one can cause leaks or poor filtration. Brita MAXTRA PRO cartridges fit the full Brita Marella, Elemaris, and Style range, but they do not fit older MAXTRA (non-Pro) jugs without an adapter. FilterLogic's Universal 6-pack is designed to be compatible with Brita Maxtra+, PerfectFit, Maxtra Pro All-in-1, and even Bosch Tassimo machines, making it a flexible option if your household runs multiple appliances. Aqua Optima Evolve+ cartridges are proprietary to Aqua Optima and LAICA jugs. Always check your jug's model number before ordering, as a mismatched cartridge is a common and frustrating mistake. If you are unsure, the jug's manual or the manufacturer's website will list compatible part numbers.
03What the filter actually removes
Different cartridge formulations target different contaminants. Brita MAXTRA PRO Pure Performance is certified to reduce chlorine, PFAS (per- and polyfluoroalkyl substances), pesticides, and limescale, making it the strongest all-round option in the Brita range. The Limescale Expert variant prioritises appliance protection, which matters most if you live in a hard-water area and want to extend the life of your kettle or coffee machine. Waterdrop's NSF-certified PT-05B cartridge is independently tested, which adds a layer of credibility beyond manufacturer claims. FilterLogic's universal cartridges reduce chlorine and limescale but do not carry PFAS certification. If PFAS reduction is a priority for you, stick to NSF-certified or Brita Pure Performance cartridges and check the certification number on the packaging.
04Cost per litre and value over time
The upfront jug price is almost irrelevant compared to ongoing cartridge costs. A Brita MAXTRA PRO Pure Performance 12-pack currently costs £39.93, which works out to roughly £3.33 per cartridge. At one cartridge per month, that is £40 per year. FilterLogic's 6-pack at £12.49 brings the per-cartridge cost to around £2.08, less than half the price. The Waterdrop PT-05B jug at £13.49 includes a 3-month cartridge, so the first year's running cost is low if you replace it quarterly. However, quarterly replacement in a hard-water area is not recommended. Factor in your local water hardness (check your supplier's website) when calculating true annual spend. Buying on Subscribe and Save via Amazon can shave a further 5–15% off cartridge costs.
Our top picks
Best for hard-water areas and PFAS reductionBRITA MAXTRA PRO Pure Performance Water
At £39.93 for a 12-pack (down from a 90-day high of £43.88), the Brita MAXTRA PRO Pure Performance works out to £3.33 per cartridge. It is the only option here certified to reduce PFAS, pesticides, chlorine, and limescale in a single pass. If you live in London or the South East, where tap water is notably hard, this is the cartridge to fit in your Brita Marella or Elemaris jug.
Best budget alternative to branded Brita cartridgesFilterLogic Universal 6 Pack Filter Cartridges
At £2.08 per cartridge, it undercuts Brita's own refills by more than a third. Compatibility covers Brita Maxtra+, PerfectFit, Maxtra Pro All-in-1, Marella jugs, and Bosch Tassimo machines, so one order covers multiple appliances in the same kitchen.
Best jug-and-cartridge bundle for new buyersAqua Optima Liscia Water Filter Jug
The Aqua Optima Liscia 2.5L with 6 Evolve+ cartridges costs £17.60, giving you six months of filtration included. The jug is dishwasher-friendly and fridge-sized at 2.5L, fitting neatly in a standard 600mm-wide fridge door shelf.
Best compact jug for small kitchens or officesWaterdrop PT-05B Elfin Water Filter Jug
The Waterdrop PT-05B Elfin holds 2.5L and is NSF certified, a meaningful independent quality mark. At £13.49 (its 90-day low was £12.59), it is one of the most affordable entry points in this category. The included cartridge is rated for 3 months, though in hard-water areas you should treat that as a maximum rather than a target.
Best for protecting kettles and coffee machinesBRITA MAXTRA PRO Limescale Expert Water
The Brita MAXTRA PRO Limescale Expert 3-pack costs £13.99, down from a 90-day high of the same price, so it has held steady. It is formulated specifically to reduce limescale build-up, which is the primary cause of element failure in UK kettles running on 240V mains. If your kettle needs descaling every few weeks, fitting one of these in your filter jug will slow that cycle considerably.
Frequently asked
How often should I change my water filter cartridge in the UK?
Most manufacturers recommend every 4 weeks or after 100–150 litres, whichever comes first. In hard-water areas such as London, the South East, and the East Midlands, the cartridge becomes saturated with limescale faster, so err towards the shorter interval. A 2.5L jug refilled three times daily reaches 100 litres in about 13 days. Use your jug's built-in timer if it has one, or simply write the change date on a piece of tape on the base.
Are FilterLogic cartridges as good as genuine Brita MAXTRA?
FilterLogic cartridges reduce chlorine and limescale effectively and are compatible with a wide range of Brita and Bosch Tassimo appliances. They cost roughly £2.08 each versus £3.33 for a genuine Brita MAXTRA PRO Pure Performance cartridge. The key difference is certification: Brita's Pure Performance variant is certified to reduce PFAS and pesticides, which FilterLogic does not claim. For everyday taste improvement and limescale reduction, FilterLogic performs well. For PFAS reduction, choose a certified cartridge.
Will a water filter jug fit in my fridge?
Most 2.5L filter jugs, including the Aqua Optima Liscia and Waterdrop PT-05B, are designed to fit in a standard fridge door shelf, which is typically 100–120mm deep. The Brita Marella XL holds 3.5L and is taller, so measure your fridge shelf height before buying. Both the Aqua Optima Liscia and Brita Marella are listed as fridge-friendly by their manufacturers. If space is tight, a 2.5L slim-profile jug is the safer choice.
What does NSF certification mean on a water filter?
NSF International is an independent US-based testing body that verifies a filter's claims against specific contaminants. NSF/ANSI Standard 42 covers aesthetic reduction (chlorine, taste, odour). Standard 53 covers health-related contaminants. When a cartridge carries NSF certification, a third party has tested it, not just the manufacturer. The Waterdrop PT-05B carries NSF certification, which adds credibility to its filtration claims. Always check which NSF standard applies, as the number tells you what has actually been tested.
Can I use Brita MAXTRA PRO cartridges in an older Brita jug?
Brita MAXTRA PRO cartridges are designed for current Brita jugs including the Marella, Elemaris, and Style ranges. They are not directly compatible with older MAXTRA (non-Pro) jugs without a specific adapter. Check the base of your jug or the Brita website for your model number. If you have an older jug, FilterLogic's Universal 6-pack may offer broader compatibility and is worth checking against your specific model before purchasing.