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Water filter cartridge compatibility guide
Identify cartridge families and use six source-linked replacement decisions to check adapters, generation exclusions and missing model information before buying.
Identify the equipment before the refill
The most useful information is usually on the device rather than the shopping result. Find the jug, bottle, tap-filter or housing model, then read the cartridge name in its instructions. Keep a photograph of the label and the old cartridge markings. For an installed system, record each housing position separately: one cupboard can contain several consumables that do different jobs.
A retailer title such as “fits BRITA” leaves several questions unanswered. Is it for an oval MAXTRA funnel, an older Classic jug, a MicroDisc bottle or an ON TAP housing? Does it include an adapter? Which generation is excluded? Answer these before comparing pack prices. A high-capacity filter from the wrong family is still the wrong purchase.
Use the directory below to find the right family guide. It is a starting point for household systems covered here, rather than a universal parts catalogue. If your exact device is absent, use its manufacturer’s manual instead of choosing the closest-looking row.
Cartridge families at a glance
| Device or family | Replacement to investigate | Important boundary |
|---|---|---|
| BRITA MAXTRA / MAXTRA+ jug | MAXTRA PRO | Check the MAXTRA-family funnel; Classic is separate. |
| BRITA Classic equipment | Classic | Do not buy MAXTRA just because it is newer. |
| BRITA MicroDisc bottle or carafe | MicroDisc | Disc format; bottle and carafe volume limits differ. |
| Aqua Optima / compatible oval jug | Evolve+ | Specified PerfectFit jugs need the key. |
| BRITA ON TAP | Correct ON TAP generation | Current V-MF fit guidance excludes pre-2019 systems. |
| Doulton mains-pressure housing | Named element and fitting | Code, thread and housing must agree. |
| Legacy ZeroWater or newer Culligan jug | Screw-in or drop-in family | The two connections are not interchangeable. |
| BWT jug | Named sealed cartridge or refill system | Loose granules do not refill a sealed disposable cartridge. |
| Philips jug | Model-matched Micro X-Clean family | Do not substitute a tap-filter or unrelated Philips cartridge. |
| Aarke Purifier or PHOX jug | Aarke doses or PHOX refills | The reusable shell and its maker's media dose form one system. |
| British Berkefeld gravity system | Compatible gravity candles | Do not transfer pressure-housing fit or mix candle grades. |
| GROHE Blue installation | S, M, L or named specialist filter | Check the exact system generation, head and service space. |
| BRITA P-series filter tap | P 1000 or P 3000 | Confirm head support, indicator settings and removal clearance. |
| Waterdrop G3P600 | Its CF, CB and RO stages | Each stage has a different role and change routine. |
| Countertop RO appliance | The exact appliance's replacement code | C1RF, K19RFG and A2RF are separate families. |
Our analysis: six replacement decisions where the details change the answer
We compared the connection and generation rules in Aqua Optima, BRITA, Culligan and Doulton’s published guidance, then applied them to six common shopping situations. This table adds a decision to the family directory: stop at an explicit mismatch, check a conditional route, or resolve missing identity information.
| Device and candidate refill | Decision | Why the result changes | Next step and source |
|---|---|---|---|
| Listed BRITA PerfectFit jug; no suitable compatibility key available Considering: Standard Evolve+ pack without the compatibility key | Stop: required accessory missing | Aqua Optima identifies the key as necessary for the specified PerfectFit connection. A matching oval shape does not supply that accessory. | Choose the correct Evolve+ pack with its key and follow the exact jug guidance. Aqua Optima fit guidance. |
| The same listed PerfectFit jug Considering: Standard Evolve+ pack with the specified key | Check the remaining conditions | The adapter requirement can be met, but the exact jug must still be covered and the key must be fitted as directed. | Retain the jug identity, current fit list and key instructions together; then compare the pack price. Aqua Optima fit guidance. |
| Legacy ZeroWater jug with a screw-in filter Considering: Newer Culligan with ZeroWater Technology drop-in filter | Stop: different connection generation | Culligan identifies legacy screw-in and newer drop-in filters as separate, incompatible systems. | Use the legacy screw-in replacement route; the shared ZeroWater name does not settle fit. Culligan generation guide. |
| BRITA ON TAP version released before 2019 Considering: Current ON TAP V-MF refill | Stop: published exclusion | BRITA’s fit statement excludes the pre-2019 versions. A newer cartridge name cannot override that exclusion. | Resolve the exact older model and its permitted replacement route before buying. BRITA V-MF fit statement. |
| Identified earlier ON TAP HF with digital display Considering: Current ON TAP V-MF refill | Check the remaining conditions | BRITA specifically lists this earlier HF version. “Old” by itself is therefore not enough to reject or approve an ON TAP replacement. | Confirm that the housing really is the listed HF version and use its matching fitting and flushing instructions. BRITA V-MF fit statement. |
| A ceramic element described only as “Doulton” Considering: A similar-looking replacement candle | Not enough information | Doulton directs owners to the element name and any identification code. Brand and appearance do not identify the grade or fitting. | Record the element name/code and housing; use the dedicated Doulton directory to resolve the correct fitting. Doulton identification method. |
Three conclusions that a brand-name search misses
An accessory can change the decision without changing the cartridge name. The two Evolve+ rows show why a filter-only price and a pack with the necessary key are not always like-for-like purchases. Check what is included before comparing unit prices. This analysis concerns the standard Evolve+ route in the cited guidance; do not extend it to a differently named refill. Our Evolve+ guide explains the pack and version distinctions.
Age is a clue, not a fit rule. The two ON TAP cases reach different conclusions because BRITA names an earlier HF model as supported while excluding versions from before 2019. Identify the actual housing rather than making “old” or “new” the deciding field. Keep the generation guide beside the replacement listing.
A missing identification field is a separate outcome from incompatibility. A legacy screw-in/drop-in mismatch is documented; an unidentified ceramic candle is unresolved. Calling both “probably fits” loses the distinction that determines the next useful action. The Doulton identification directory covers the element, housing and fitting record.
Method and reusable replacement record
Each row combines a stated device situation with one proposed refill and applies the cited manufacturer’s rule. The decision wording and next step are our synthesis; the underlying fit statements belong to their manufacturers. “Check the remaining conditions” is not blanket approval for a brand, and a physical-fit statement does not establish identical reduction claims, service life or warranty terms. These six situations illustrate specific decisions, not the proportion of compatible products on the market.
For your own replacement record, keep six fields together: device model and suffix; cartridge name/code; generation or connection; required accessory; named exclusion; source/manual. An unresolved field remains a question to settle before ordering. Add the pack quantity and price only after that identity record agrees with the chosen replacement.
Download the six replacement decisions and their source links (CSV). For a confirmed fit, use the running-cost analysis to compare the replacement schedule and your actual pack price.
Replacement packs after confirming the family
MAXTRA PRO: select the purpose after establishing fit
For a compatible MAXTRA-family jug, Pure Performance and Limescale Expert offer a choice within the family. The cartridge comparison explains when a scale-focused refill is worth considering. Switching purpose within the confirmed family is different from switching to an unrelated cartridge format.
BRITA MAXTRA PRO Pure Performance · 6 pack
The everyday-purpose MAXTRA PRO replacement for compatible BRITA jugs and Flow. Compare this six-pack with the cartridges already included in your chosen starter bundle.
- Pack
- 6 cartridges
- Family
- MAXTRA PRO
- Limit
- 150L / 4 weeks
Good forRestocking a compatible MAXTRA PRO system.
Watch forFour weeks can arrive long before 150 litres.
Check the MAXTRA PRO family against your jug instructions. It is not a replacement for BRITA Classic, MicroDisc or ON TAP cartridges.
Evolve+: read the adapter requirement
Aqua Optima publishes its own fit information, including the key required for the specified BRITA PerfectFit funnels. That makes it a useful example of why “oval” is not enough detail. Compare the replacement manufacturer’s instructions with the jug model, not with a photograph of a different customer’s funnel.
Aqua Optima Evolve+ · 6 pack
The Evolve+ replacement family for compatible Aqua Optima jugs and dispensers. Check the device instructions and whether one cartridge or a pair is installed.
- Pack
- 6 cartridges
- Family
- Evolve+
- Limit
- 100L / 30 days
Good forMaintaining a confirmed compatible Aqua Optima device.
Watch forDevice instructions and paired systems can change the replacement calculation.
For a PerfectFit BRITA jug, check the compatibility key is included and follow Aqua Optima’s fit guidance. Do not assume any oval cartridge will work.
Classic and MicroDisc: separate formats
Classic is the route for existing Classic-compatible equipment. MicroDisc belongs to devices designed around a small disc. Neither should be selected as an alternative cartridge for a MAXTRA funnel. Choose the replacement that maintains the equipment you already have rather than a larger pack from the wrong family.
BRITA Classic · 3 pack
A replacement pack for an existing Classic-format jug. Keep the older container in service only after confirming Classic is the family named in its instructions.
- Pack
- 3 cartridges
- Family
- Classic
- Time limit
- 4 weeks
Good forReplacing the correct older-format cartridge.
Watch forThe BRITA name alone does not establish fit.
For Classic-compatible equipment only. It does not replace an oval MAXTRA cartridge, a MicroDisc or an ON TAP refill.
BRITA MicroDisc · 3 pack
Replacement discs for compatible BRITA filter bottles and carafes. Choose by the device instructions; a bottle and a gravity carafe have different volume limits.
- Pack
- 3 discs
- Family
- MicroDisc
- Time limit
- 4 weeks
Good forMaintaining a MicroDisc drinking-water device.
Watch for60L in bottles differs from 150L in carafes.
Use only in a device designed for MicroDisc. It retains calcium and magnesium and is not the hardness-reducing replacement for a MAXTRA jug.
ON TAP and Doulton: the housing matters
An ON TAP name needs a generation check. A Doulton name needs the full element identity and connection. For both, retain the old markings until the new item has been matched. The linked guides explain the exclusions; neither jug-cartridge advice nor a generic “10-inch filter” description settles those questions.
BRITA ON TAP V-MF · 2 pack
A two-cartridge replacement pack for the compatible ON TAP family. Keep the V-MF name alongside the system model when comparing refill listings.
- Pack
- 2 cartridges
- Type
- ON TAP V-MF
- Limit
- 600L / 4 months
Good forKeeping the tap filter supplied after its initial cartridge.
Watch forNot a jug refill; check your system generation.
BRITA lists cross-compatibility with ON TAP V, Pro V-MF and the earlier HF with digital display. It excludes ON TAP versions from before 2019.
Doulton Biotect Ultra 2501 · M12 refill
The ceramic replacement for compatible Doulton M12 systems, including the HIP TRIO. Buy the exact 2501 type rather than judging by cartridge length alone.
- Pack
- 1 ceramic filter
- Fitting
- M12
- Care
- Replace around 6 months
Good forMaintaining the ceramic stage of a compatible installation.
Watch forNot a British Berkefeld gravity cartridge or an M15 refill.
This replaces the ceramic element; it does not renew the HIP TRIO’s two separate pre-filters. Follow their own replacement instructions as well.
Make a five-point check before ordering
- Device: write down the exact model, including any suffix.
- Cartridge: match the family and named version, not just the brand.
- Connection: confirm the funnel feature, key, thread or seal arrangement.
- Pack: check the selected listing variant, cartridge count and included accessories.
- Instructions: confirm preparation and replacement limits for the new cartridge.
Once those points agree, compare the delivered price per cartridge and use the running-cost calculator. Keep the refill name in a note with the device model so the next purchase starts from a confirmed match.
Do not trim a cartridge, force a lid closed or defeat a flow-control feature to make a purchase fit. If an apparently correct replacement does not seat, stop and check the preparation and fitting instructions. For an installed housing, follow its isolation and depressurisation procedure before opening it; obtain help if the system cannot be safely identified.
More replacement-filter families
- ZeroWater cartridge compatibility: legacy filters vs newer Culligan systems
- BWT jug cartridge compatibility: sealed cartridges, refillable cartridges and granules
- Philips jug cartridge compatibility: matching Micro X-Clean filters to your model
For paired Evolve+ replacements, see the Perfect Pour dispenser guide.
Installed-system refills need a complete parts record
For a filter tap, keep the tap model, head code and cartridge identity together. A replacement cartridge is not a starter kit: it may exclude the head, flow meter, connecting hoses and installation parts. Our GROHE Blue Pure guide and BRITA three-way tap guide explain those complete-system purchases before their replacement comparisons.
Record every stage of a reverse-osmosis system separately. A carbon prefilter, membrane and optional mineral cartridge do different jobs. A matching tube diameter alone does not establish an approved retrofit. Use the RO remineralisation guide for that distinction, and the actual appliance instructions for the permitted change and flushing sequence.
If replacement is being considered because the flow has fallen, diagnose the affected water path first. The under-sink low-flow guide separates cartridge restrictions from supply, hose and plumbing problems. A new refill cannot correct a leaking fitting, an incompatible head or an obstructed pipe.
Questions before you buy
Can I use any cartridge that fits inside the funnel?
No. The seal, outlet and any flow-control mechanism must work with the device. A cartridge can sit inside a funnel without making the required connection. Match the exact device against the replacement manufacturer’s current fit list.
Does MAXTRA PRO replace a BRITA Classic cartridge?
No. Classic uses a separate format. Use a Classic cartridge in equipment whose instructions specify Classic; MAXTRA-family jugs use the oval MAXTRA format.
Can Evolve+ work in a BRITA PerfectFit jug?
Aqua Optima specifies the compatibility key for the PerfectFit jugs covered by its guidance. Check that the key is supplied and follow its fitting instructions for your jug. Do not assume an older pack includes it.
Are all Doulton ceramic candles interchangeable?
No. Match the name, code, fitting and housing. A Biotect Ultra 2501 M12 element is different from a British Berkefeld gravity element or an M15 cartridge, even when both look like ceramic candles.
Should I replace the whole jug if I cannot identify the filter?
Identify the equipment first. Photograph its label and existing cartridge markings and ask the manufacturer. A sound jug may simply need the correct replacement; buying a new container does not resolve uncertainty about an installed system.