Waterdrop currently lists G3-N3CB for up to 12 months or 1,100 gallons, at $29.99 one-time.
What G3-N3CB is
G3-N3CB is the carbon-block stage in the Waterdrop G3-family replacement set.
Published lifespan
Waterdrop rates it for up to 12 months or 1,100 gallons depending on water condition.
Current price
The current one-time price shown by Waterdrop is $29.99.
Pairing with the other cartridges
A G3P800 owner normally replaces the CF stage more often and the RO membrane less often, so filter alerts should be tracked by cartridge rather than replacing all three together.
How to verify fit before buying Waterdrop G3-N3CB Replacement Filter: Life, Price and Fit
Treat compatibility as a model-number decision, not a shape-matching exercise. Start with the appliance or system model label, then confirm the exact cartridge or replacement code listed by the manufacturer. Similar-looking filters can use different tabs, seals, RFID features or bypass interfaces, so a cartridge that appears to fit can still leak, restrict flow or fail to lock correctly.
For aftermarket replacements, separate physical compatibility from filtration performance. A seller can correctly state that a cartridge fits a refrigerator while the contaminant-reduction scope differs from the original filter. If lead, cysts, PFAS or another health-related claim matters, verify the exact replacement model in the current certification or performance documentation rather than assuming an OEM-equivalent claim set.
Compare recurring cost, availability and replacement risk
Replacement products should be evaluated over several service cycles. Multiply the current cartridge price by the realistic replacement frequency, add shipping, and check whether the same model is consistently stocked. A low first-purchase price is less useful if the cartridge becomes difficult to source or if replacement intervals are short.
Watch for vague phrases such as “uses certified media” or “tested to a standard.” Finished-product certification is stronger evidence than a statement about one component. For marketplace listings, clear manufacturer identity, exact model numbers, return policies and traceable certification reduce the risk of counterfeit-style or poorly fitting replacements.