# Waterdrop G3P800 Replacement Filters: Which Parts Fit, and What the G3 and G3P600 Share > The Waterdrop G3P800 takes the WD-G3-N1CF (6 months), WD-G3-N3CB (12 months) and WD-G3P800-N2RO membrane (24 months). Only the membrane differs across the G3 line. | | | |---|---| | Source | https://ownerspec.com/water/parts/waterdrop-g3-g3p800-replacement-filters/ | | Publisher | OwnerSpec (https://ownerspec.com/) | | Published | 2026-09-12 | | Updated | 2026-09-12 | | Facts verified | 2026-09-12 | | Disclosure | Contains affiliate links. OwnerSpec may earn a commission at no cost to the reader. | --- ## Short answer The Waterdrop G3P800 takes three twist-and-lock filters plus an optional fourth. Waterdrop's G3P800 replacement page rates the WD-G3-N1CF composite pre-filter at 6 months or 550 gallons, the WD-G3-N3CB carbon block at 12 months or 1,100 gallons, and the WD-G3P800-N2RO reverse osmosis membrane at 24 months, with 2,200 gallons in its spec table. The optional WD-MNR35 remineralization filter is rated 12 months or 1,100 gallons on its own page. The pre-filter and carbon block are the same part numbers across the G3-W (400 GPD), G3P600 and G3P800; the membrane is not: the G3-W uses the WD-G3-N2RO, the G3P600 uses the WD-G3P600-RO, and the Amazon.de listing for the G3-CFCBRO three-filter set states it is not for the G3P600 and G3P800. The one spec that must match is the system model printed on the membrane. G2 and X series filters are different parts and are not listed as compatible. The part people get wrong is the membrane: the base G3 three-filter set supplies the right pre-filter and the right carbon block for a G3P800, and the wrong membrane. ## Which cartridges fit the G3P800? Waterdrop's G3P800 replacement page lists three filters and rates each on its own clock. Every interval and price in the table is that page's figure on 12 September 2026, except where the part's own page is named. | Part | Position | Interval (Waterdrop's figure) | Certification stated | Price, waterdropfilter.com | |---|---|---|---|---| | WD-G3-N1CF | Stage 1, composite pre-filter | 6 months or 550 gallons (551 on the N1CF page) | NSF/ANSI 58 and 372 (N1CF page) | $29.99 | | WD-G3-N3CB | Carbon block | 12 months or 1,100 gallons | None stated for the part; the system is listed to NSF/ANSI 42, 53, 58 and 372 | $29.99 | | WD-G3P800-N2RO | Reverse osmosis membrane | 24 months; 2,200 gallons in the spec table, "up to 2,900 gallons" in the copy on the same page | None stated for the part; system listing as above | $139.99 | | WD-MNR35 (optional) | Remineralization, after the membrane | 12 months or 1,100 gallons (MNR35 page) | RoHS only; no NSF/ANSI listing | $33.99, or $32.29 on 12-month autoship | The same page sells the N1CF, N3CB and G3P800-N2RO together as a set at $89.97, which on that day was below the membrane's own price of $139.99. Check the live page before ordering either way. Two of the four filters have a standalone Amazon.com listing, sold by the Waterdrop Store: the WD-G3-N1CF and the WD-G3-N3CB. The G3P800-N2RO membrane and the MNR35 still route to waterdropfilter.com through Amazon's "shop other stores directly" panel, with no standalone listing of their own. The system the filters serve, per the same spec table: | G3P800 spec | Waterdrop's published figure | |---|---| | Flow rate | 800 GPD | | Pure-to-drain ratio | 3:1 | | Filtration | 10-stage | | Certification | NSF/ANSI 42, 53, 58 and 372 | | Dimensions | 18.11 x 5.67 x 17.73 in | | Weight | 32.4 lb | Pure-to-drain ratio is the gallons of filtered water the membrane produces for every gallon it sends to drain. NSF/ANSI 58 covers reverse osmosis system performance and NSF/ANSI 372 covers the lead content of wetted components; neither covers a part that does not carry it. ## What else fits the same housing? The G3 line shares two of its three filters and splits the third: Waterdrop's pages give three membrane part numbers at three prices, one per system model. | Filter | G3-W (400 GPD) | G3P600 | G3P800 | |---|---|---|---| | Composite pre-filter | WD-G3-N1CF | WD-G3-N1CF | WD-G3-N1CF | | Carbon block | WD-G3-N3CB | WD-G3-N3CB | WD-G3-N3CB | | RO membrane | WD-G3-N2RO, $92.99 | WD-G3P600-RO, $109.99; 24 months or 2,200 gallons; NSF/ANSI 58 and 372; 4.3 x 4.3 x 15 in | WD-G3P800-N2RO, $139.99; 24 months; 2,200 gallons (spec table) | | Remineralization (optional) | WD-MNR35 (G3 series listed; the G3-W is not named) | WD-MNR35 | WD-MNR35 | The G3-CFCBRO set is the trap. It is one N1CF, one N3CB and one WD-G3-N2RO, and its Amazon.de listing says in the title that it is not for the G3P600 and G3P800. The first two parts are correct for every G3; the membrane is the 400 GPD part. Across Waterdrop's other under-sink lines, only the optional remineralization filter crosses: | Series | Pre-filter and carbon block | RO membrane | WD-MNR35 | |---|---|---|---| | G3 (G3-W, G3P600, G3P800) | WD-G3-N1CF and WD-G3-N3CB | Per model, table above | Listed (G3P600 and G3P800 named) | | G2 (G2P400, G2P600) | G3 parts not listed as compatible | G3 membranes not listed | Listed | | D series (D6) | G3 parts not listed as compatible | G3 membranes not listed | Listed | | X series | Not listed | Not listed | Not on the MNR35 list | Waterdrop's compatibility lists are the only fit data it publishes. This page does not claim whether an unlisted G2 or X cartridge physically seats in a G3 housing, only that Waterdrop does not list it. ## How often do they need replacing? Waterdrop's figures are months or gallons, whichever arrives first: 6 months or 550 gallons for the N1CF, 12 months or 1,100 gallons for the N3CB, 24 months for the G3P800-N2RO. The gallons decide in a household that draws all its drinking and cooking water from the tap: divide each capacity by the gallons the tap dispenses in a day to see whether the months ever arrive. The membrane's capacity is the figure to read twice. Waterdrop's page gives 2,200 gallons in its spec table and "up to 2,900 gallons" in the copy below it. Plan on 2,200 and read the live page when you order. The MNR35 and the N3CB share an interval, 12 months or 1,100 gallons, so change them together. The MNR35 sits after the membrane, the last stage the water passes, and no NSF/ANSI listing covers it. **Which parts to buy** No cross-brand cartridge was found for the G3P800's twist-and-lock housings, so there is no cheaper fit to admit to. The flaw is on the manufacturer's page: two capacities for one membrane, and a three-filter set at $89.97 listed below the membrane alone at $139.99. Order the N1CF and N3CB by part number, since they fit every G3, and order the membrane by system model: WD-G3P800-N2RO for the G3P800, WD-G3P600-RO for the G3P600, WD-G3-N2RO for the G3-W. Skip the MNR35 if you want every stage to carry an NSF/ANSI listing; it carries RoHS only. Skip this page if the complaint is scale or staining at every tap: the G3P800 is a one-tap unit, and the [whole-house filter flow rate calculator](/water/calculators/whole-house-filter-flow-rate-calculator/) and the [hard water and white scale guide](/water/guides/hard-water-white-scale/) cover that. ## The picks - **Waterdrop WD-G3-N1CF**: Stage 1, composite pre-filter: shared across the G3 line (6 months or 550 gallons; NSF/ANSI 58 and 372; fits G3-W, G3P600 and G3P800; $29.99 direct from Waterdrop) Amazon: https://www.amazon.com/dp/B07NZSSBWC/?tag=ownerspec-20 - **Waterdrop WD-G3-N3CB**: Carbon block: shared across the G3 line (12 months or 1,100 gallons; fits G3-W, G3P600 and G3P800; $29.99 direct from Waterdrop) Amazon: https://www.amazon.com/dp/B07NXQ3S87/?tag=ownerspec-20 - **Waterdrop WD-G3P800-N2RO**: The G3P800's membrane: not the G3-W or G3P600 part (24 months; 2,200 gallons in the spec table (2,900 in the page copy); $139.99 direct from Waterdrop) - **Waterdrop WD-MNR35**: Optional remineralization stage, after the membrane (12 months or 1,100 gallons; 2.6 x 2.6 x 11 in; RoHS only, no NSF listing; fits G3, G2 and D series; $33.99 direct) ## Frequently asked questions ### Does the Waterdrop G3 (400 GPD) replacement set fit the G3P800? Two of its three filters do. The G3-CFCBRO set bundles one WD-G3-N1CF pre-filter, one WD-G3-N3CB carbon block and one WD-G3-N2RO membrane, and the Amazon.de listing for the set states it is not for the G3P600 and G3P800. The pre-filter and carbon block are the same part numbers across the G3 line; the WD-G3-N2RO membrane is the 400 GPD part. ### Which membrane does the Waterdrop G3P800 use, and how long does it last? Waterdrop's G3P800 replacement page names the WD-G3P800-N2RO and rates it at 24 months. The same page gives two capacities: 2,200 gallons in its spec table and up to 2,900 gallons in the copy further down. Plan on the 2,200 figure. The G3-W uses the WD-G3-N2RO and the G3P600 the WD-G3P600-RO; the three membranes are separate part numbers. ### Is the Waterdrop MNR35 remineralization filter NSF certified? No. Waterdrop's WD-MNR35 page lists RoHS as its only certification, which is a restriction-of-hazardous-substances materials standard, not a drinking water treatment standard. The G3P800 system itself is listed to NSF/ANSI 42, 53, 58 and 372, and the WD-G3-N1CF pre-filter page cites NSF/ANSI 58 and 372. The MNR35 is rated 12 months or 1,100 gallons. ### Do Waterdrop G2 or X series filters fit the G3P800? Waterdrop does not list them as compatible. The WD-G3-N1CF and WD-G3-N3CB pages name only the G3 series, and the WD-MNR35 page lists the G3P800, G3P600, D6, G2P600 and G2P400 with no X series model on it. The only part that crosses lines is the MNR35, which is optional. This page makes no claim about whether an unlisted cartridge physically seats in the housing. ### Can I buy Waterdrop G3P800 replacement filters on Amazon? On 12 September 2026, two individual filters had a standalone Amazon.com listing sold by the Waterdrop Store: the WD-G3-N1CF and the WD-G3-N3CB. The WD-G3P800-N2RO, WD-G3P600-RO, WD-G3-N2RO and WD-MNR35 still routed to waterdropfilter.com through Amazon's 'shop other stores directly' panel. Waterdrop's direct prices that day were $29.99 for each of the N1CF and N3CB and $139.99 for the G3P800 membrane. ## Sources - [Waterdrop, G3P800 RO System Replacement Filters (800 GPD) product and spec page](https://www.waterdropfilter.com/products/waterdrop-g3p800-ro-system-replacement-filters) - [Waterdrop, WD-G3-N1CF filter for the WD-G3-W reverse osmosis system product page](https://www.waterdropfilter.com/products/wd-g3-n1cf) - [Waterdrop, WD-G3-N2RO filter for the WD-G3-W reverse osmosis system product page](https://www.waterdropfilter.com/products/wd-g3-n2ro) - [Waterdrop, WD-G3P600-RO filter for the G3P600 reverse osmosis system product page](https://www.waterdropfilter.com/products/g3p600-ro-system-replacement-filters) - [Waterdrop, WD-MNR35 remineralization filter product page (specifications and compatibility list only)](https://www.waterdropfilter.com/products/wd-mnr35) - [Amazon.de listing for the Waterdrop G3-CFCBRO replacement set (listing copy only: the compatibility line)](https://www.amazon.de/s?k=Waterdrop+G3-CFCBRO+Replacement+Filter) - [Amazon.com search results for Waterdrop WD-G3-N3CB (checked only for standalone listings and the 'shop other stores directly' panel)](https://www.amazon.com/s?k=Waterdrop+WD-G3-N3CB+Filter+G3P800+G3) - [NSF, NSF/ANSI 58: Reverse Osmosis Drinking Water Treatment Systems](https://www.nsf.org/knowledge-library/nsf-ansi-58-reverse-osmosis-drinking-water-treatment-systems) - [NSF, NSF/ANSI 372: Drinking Water System Components, Lead Content](https://www.nsf.org/knowledge-library/nsf-ansi-372-drinking-water-system-components-lead-content) --- Citation: OwnerSpec, "Waterdrop G3P800 Replacement Filters: Which Parts Fit, and What the G3 and G3P600 Share", https://ownerspec.com/water/parts/waterdrop-g3-g3p800-replacement-filters/, updated 12 September 2026. 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