Replacement Cartridge Guide: Pitcher, Under-Sink, RO and Whole-House Filters

Pitcher, dispenser and faucet cartridges

Exact product links are shown only where Amazon’s listing names the same part and was new and in stock when checked. The Clearly Filtered row is a search because the Amazon listings don’t show the CF-PRF part number, and different listings state different certification claims. Stock and sellers change.

What to know about each pitcher and faucet brand

Brita. Brita’s support page sorts its filters by color. The Original (Standard) filter, white, is for standard Brita pitchers. The Elite filter, blue, “will fit with all Brita systems.” The gray Stream filter is only for Stream pitchers. Brita bases its timing on 11 glasses a day, and says hard water may need earlier changes. Pitchers with the electronic indicator need it set to the Elite filter’s 120-gallon mode. Our pitcher roundup covers the Tahoe and its certification listing.

PUR. PUR sells two pitcher and dispenser cartridges: the PLUS filter (PPF951K) and the basic Pitcher Filter (PPF900Z). Each lasts 40 gallons or 2 months. PUR’s faucet cartridge, RF-9999, lasts 100 gallons or 3 months. PUR says genuine PUR filters are the only ones certified for its systems, so a lookalike can fit without carrying the same certification. Our PUR PLUS FM2500V review covers the faucet system.

ZeroWater. ZeroWater has two generations whose filters don’t mix and match, according to Culligan’s own pages. A legacy system has the ZeroWater logo, a bottom-threaded filter that screws into the base of the upper reservoir, and a lid that comes off entirely. A newer system has the Culligan logo, a filter that drops in from the top, and a sliding lid. IAPMO R&T’s certificate for Zero Technologies lists ZR-017 among the filters for the ZP-010 and other ZeroWater pitchers and dispensers. The interval is set by your water: moderate tap water can yield 40 gallons or more per filter, and very high TDS water about 8 to 15, according to Culligan, which is why both makers tell you to go by the meter reading. Our roundup lists the ZP-010’s certified capacity at 15 gallons.

LifeStraw. The Home pitchers use two filters on different schedules, so you track two dates. The membrane microfilter lasts about a year and the carbon and ion exchange filter about 2 months, per LifeStraw. LifeStraw says all Home replacement filters fit every LifeStraw Home pitcher and dispenser.

Clearly Filtered. Clearly Filtered’s performance page names the replacement element CF-PRF with a 100-gallon rating. The pitcher holds about half a gallon, so a household that refills several times a day reaches 100 gallons well before six months. Our Clearly Filtered review has the certification details.

Under-sink filter replacement cartridges

Under-sink systems take one cartridge or one cartridge set, named on the system’s data sheet. These are the four systems on our under-sink filter list .

Exact product links are shown only where Amazon’s listing names the same part and was new and in stock when checked. The AQ-C3M-R listing is titled with Aquasana’s older AQ-5300+R code and names both the AQ-C3M-R and the AQ-6300M. The Multipure row is a search because the Amazon results we found were Multipure’s CB6 filter for other systems and third-party look-alikes, not the CBLX. Stock and sellers change.

Check the model suffix. Aquasana’s Amazon listing for a different set, AQ-C3-R, says it fits the earlier AQ-5300 and AQ-6300 systems, so a three-stage Aquasana filter isn’t automatically the right one for an AQ-6300M. Two 3M systems, two cartridges. The 3MFF100 and the AP-DWS1000 look alike under a sink, but Solventum lists the 3MFF101 for the 3MFF100 and the AP-DW80/90 for the AP-DWS1000 . The AP-DWS1000’s built-in meter shuts the system off after 625 gallons, so you have no filtered water until you change the cartridges. Our under-sink list covers the certification listings for each system.

Reverse osmosis replacement filters and membranes

An RO system has two kinds of consumables. The sediment and carbon filters are changed every few months to a year, while the membrane is rated for one to four years across the systems below. Match the membrane most carefully: APEC’s manual says a replacement should have “identical specifications, as defined by the manufacturer,” and the systems below use different membranes (the iSpring MC7 is a 75 GPD, 11.75 by 1.75-inch membrane, and the MRO500 is a 500 GPD membrane for a tankless system). These are the four RO systems on our reverse osmosis list , plus the Waterdrop G3P800 from our tankless comparison .

Aquasana SmartFlow AQ-SFRO2

Aquasana’s Amazon listings for these three parts say they are not compatible with its older OptimH2O systems, which use different sets. Aquasana’s owner’s manual gives 12 months for the membrane on typical 7.0 to 7.5 pH municipal water and says higher pH shortens membrane life. Our RO list covers this system’s certified claims.

iSpring RCC7AK-BN

iSpring’s RCC7AK page names these six parts and the four sets. The 6-month set has no post-carbon filter or membrane, the 1-year set has the post-carbon filter but no membrane, and the 2- and 3-year sets include one membrane. iSpring says the current FT15 and FA15 filters have push-fit quick connections. The FT15 and FA15 rows are searches because the Amazon results we found were other iSpring parts, such as the FT15-N, FT15B, FT15Q, FA15-N and FA15US, not the FT15 and FA15 themselves.

iSpring RO500-BN

iSpring’s replacement table lists the FCF500 at up to 6 months, while an FAQ on the same RO500-BN page says stages 1 and 3 last a year. If you can’t tell which applies, use the shorter interval. The pack contents are from the Amazon listings for the F3-RO500 and F7-RO500. Our G3P800 vs RCC7AK comparison covers how the tankless design differs from a tank system.

APEC Essence ROES-50

APEC’s ROES-50 manual lists the stage-4 membrane as “MEM-ES-75 or MEM-ES-50”; APEC’s parts page lists the MEM-ES-50 for the ROES-50. The manual also recommends replacing the filter housing O-rings every year or when you change the three pre-filters, and says the membrane should be replaced with one of identical specifications. Our ROES-50 review covers cabinet fit and pressure.

Waterdrop G3P800

Waterdrop says the G3P800 membrane is a different part from the one for the smaller G3 (WD-G3-N2RO), so match the full model name. Waterdrop lists the first-stage composite filter and the carbon block as shared with the G3P600 and G3 models.

Exact product links are shown only where Amazon’s listing names the same part and was new and in stock when checked. Stock and sellers change.

Whole-house replacement cartridges and parts

Whole-house systems either take large-diameter cartridges in housings (iSpring, 3M Aqua-Pure) or use a media tank with a pre-filter and post-filter (Aquasana). For what “10-inch,” “20-inch,” “standard” and “Big Blue” mean, and for which generic cartridges fit which housing, see our whole-house cartridge size guide . This section names the maker’s own parts for the systems on our whole-house list .

Aquasana Rhino WH-1000 and HealthShield WH-HS

Aquasana’s manuals for the WH-1000 and WH-HS list the same pre- and post-filter part numbers for both systems. They cover the standard 20-inch pre-filter and an optional low-maintenance pre-filter, and give the tank capacity in their warranty charts: 10 years or 1,000,000 gallons for the WH-1000 and 2 years or 165,000 gallons for the WH-HS. The EQ-303-20 listing on Amazon is a 3-pack. The WH-HS-R row is a search because we found no Amazon listing for that tank.

3M Aqua-Pure AP903 and AP904

Solventum’s AP900 heads use sanitary quick-change cartridges, so buy the AP900 cartridge Solventum names rather than a standard 4.5 by 20-inch one; our size guide explains the format and lists the AP902’s AP910R. Solventum says the AP917HD cartridges give approximately one year of life, depending on water quality.

iSpring WGB32B, WGB32BM and UVF55FS

The WGB32B takes one FP25B and two FC25B. The WGB32BM swaps one carbon block for the FM25B iron and manganese cartridge, which iSpring rates at 50,000 gallons at 3.0 ppm iron, a lower figure than its sediment and carbon cartridges. The UVF55FS is a UV disinfection unit rather than a filter: it takes a lamp and a quartz sleeve, and our UVF55FS review warns that UVF55 (without FS) parts aren’t interchangeable just because the wattage matches. The UVB55FS row is a search because the Amazon results we found were third-party lamps for a different brand of unit. Our WGB32BM review covers that system’s three stages, and the size guide covers fit and format.

Exact product links are shown only where Amazon’s listing names the same part and was new and in stock when checked. Stock and sellers change.

Why we link only the maker’s cartridges

Third-party “compatible” cartridges are easy to find and cost less to list, but the makers’ own statements point to the genuine ones. PUR’s cartridge pages say off-brand filters “are not tested nor certified to filter the same as” genuine PUR filters in PUR systems, and that compatible replacements “are not guaranteed to offer the same water quality.” Aquasana’s manuals say use of parts from other manufacturers “may result in loss of contaminant reduction performance, system damage, or failure,” and APEC’s says non-APEC filters “may clog up the RO system and damage the membrane.” Certifiers list a pitcher and filter pair, so a certification belongs to the exact combination. Our certification guide shows how to check one.

Set a change date you can keep

• Write the install date and the part number on the box, or in the kitchen filter maintenance record .
• Count gallons, not months, if you filter a lot of water. Brita’s “about 2 months” for a 40-gallon filter assumes 11 glasses a day, roughly 0.7 gallon if a glass is 8 ounces. A household that filters 1.5 gallons a day reaches 40 gallons in under a month.
• For ZeroWater, test with the meter that came with it.
• For RO and under-sink systems, track each part separately. The membrane, the carbon filters and a remineralizer or alkaline filter run on different clocks, and sets like iSpring’s F4AK or F9K leave the membrane out.
• After changing RO filters or a membrane, follow the maker’s flush steps. APEC’s manual, for example, says to drain the first tank of water after fitting a new membrane.
• For whole-house cartridges, watch pressure as well as the calendar. A growing pressure drop is a replacement signal; see our pressure-drop guide .
• If your water has a health notice, follow your utility’s or health department’s instructions. These cartridges are not made to disinfect unsafe water.

Other filters and cartridges

For other systems, see the refrigerator water filter replacement guide for OEM versus generic fridge filters, whole-house filter cartridge sizes for 10- and 20-inch housings and generic fits, and our reverse osmosis buying guide for choosing a system.

Frequently Asked Questions

Do Brita filters fit PUR or ZeroWater pitchers?

No. Each maker’s pitchers are built around its own cartridge. Brita says its Original and Elite filters fit Brita pitchers, PUR says its filters fit PUR and Beautiful by PUR systems, and ZeroWater’s legacy and newer Culligan filters don’t mix and match with each other, let alone with other brands.

How do I know when to change a ZeroWater filter?

ZeroWater and Culligan both say to replace it when the included TDS meter reads 006 or higher, or when taste or smell changes. Filter life depends on how much dissolved solid is in your tap water.

Are third-party “compatible” cartridges as good as the maker’s?

Not necessarily. PUR says off-brand filters are not tested or certified to filter the same as genuine PUR filters in PUR systems, and certifiers list a pitcher and filter pair rather than a part number alone. This guide links only the maker’s own cartridges.

Which cartridge does my under-sink filter use?

Match the system’s model number. Aquasana lists AQ-C3M-R for the AQ-6300M, Solventum lists 3MFF101 for the 3MFF100 and AP-DW80/90 for the AP-DWS1000, and Multipure lists CBLX for the Aqualuxe. Solventum names each 3M cartridge for its own system.

How often do I change a reverse osmosis membrane compared with the filters?

The membrane lasts much longer. Makers give 6 to 12 months for most sediment and carbon filters, but 2 to 3 years for iSpring’s MC7 and MRO500 membranes, 2 to 4 years for APEC’s on city water, 24 months for Waterdrop’s G3P800 membrane and 12 months for Aquasana’s SmartFlow membrane.

How often do whole-house cartridges need changing?

It depends on the system. Aquasana says to change the 20-inch pre-filter on its Rhino and HealthShield systems every 2 months (6 months for its low-maintenance pre-filter) and the 10-inch post-filter every 6 months. Solventum says its AP917HD cartridges give about a year, and iSpring gives 6 to 12 months for its WGB32B set.

Sources

• Brita: Elite Replacement Filters (OB06) , Original Pitcher and Dispenser Replacement Filters (OB03) , replacement filters FAQ (fit by filter color, replacement timing), Tahoe Water Pitcher with Elite Filter (model OB60)
• PUR: PUR PLUS Pitcher Filter, PPF951K , PUR Pitcher Filter, PPF900Z (fit, 2 months or 40 gallons, off-brand statement), PUR PLUS Faucet Filter, RF-9999 (fit, 3 months or 100 gallons)
• ZeroWater and Culligan: Legacy ZeroWater Filter and Culligan with ZeroWater Technology Filter (how to tell the two apart), When to change your ZeroWater filters (TDS 006 rule, filter life by TDS level), ZeroWater FAQ , ZeroWater 5-stage replacement filter , IAPMO R&T NSF/ANSI 53 certificate for Zero Technologies (filter model list including ZR-017)
• LifeStraw: LifeStraw Home Replacement Filters (part numbers, intervals, fit)
• Clearly Filtered: pitcher performance data (CF-PRF, 100 gallons), pitcher replacement filter (usage guide)
• Aquasana: Claryum 3-Stage Max Flow product page and AQ-6300M performance data sheet (AQ-C3M-R, 800 gallons or 6 months), SmartFlow Reverse Osmosis product page and AQ-SFRO2 owner’s manual (AQ-SFRO-S1S3, AQ-SFRO-S2, AQ-SFRO-REMIN, intervals), WH-1000 owner’s manual and WH-HS owner’s manual (pre- and post-filter part numbers and intervals, tank part numbers and warranty-chart capacity, genuine-parts statement)
• Solventum (3M Aqua-Pure): 3MFF100 system page (3MFF101, up to 12 months, 6,000 gallons), AP-DWS1000 system page (625-gallon shut-off, 6-month interval), AP-DW80/90 cartridge page (fit, catalog numbers), AP900 series cartridge page (AP917HD, AP917HD-S, AP910R, about one year of life)
• Multipure: Aqualuxe product page and Aqualuxe spec sheet (CBLX, 500 gallons, annual replacement)
• iSpring: RCC7AK product page (FP15, FG15, FC15, FT15, MC7 and FA15 intervals; F4AK, F9K, F19K75 and F28K75 sets), F4AK , F9K , F19K75 and F28K75 set pages (contents), MC7 membrane page (75 GPD, 11.75 by 1.75 inches), RO500-BN product page (FCF500, MRO500, FCB500, F3-RO500, F7-RO500 and intervals), WGB32B product page (F3WGB32B, 6 to 12 months, FC25B 12 months), FM25B and F3WGB32BM pages (iron and manganese cartridge and set), UVF55FS product page , UVB55FS lamp page and UVQ55FS sleeve page (lamp and sleeve intervals)
• APEC: ROES-50 owner’s manual (maintenance schedule, part numbers, identical-specification statement), pre-filter set FILTER-SET-ES , membrane MEM-ES-50 , inline carbon filter FI-ES-TCR-QC and complete filter set FILTER-MAX-ES50 (fit)
• Waterdrop: WD-G3-N1CF , WD-G3P800-N2RO and WD-G3-N3CB filter pages (fit, replacement intervals and gallons)
• Amazon product data for the linked listings, checked October 19, 2026

Part numbers and intervals were checked on October 19, 2026. Better Water Guide has not tested these cartridges; this is desk research from maker pages, manuals and certifier listings.