Waterdrop RO Filter Replacement Guide: G3P600, G3P800 and G3
Every Waterdrop G3-series RO system uses three cartridges: a CF pre-filter, a CB carbon filter and an RO membrane. Two of them are shared across the G3, G3P600 and G3P800, and the membrane is specific to each model. Here is which part goes where, when to change it, and what it costs to keep the system running.
Which filter fits which system
| Cartridge | Part | Fits | Interval (per Waterdrop) |
|---|---|---|---|
| CF pre-filter | WD-G3-N1CF | G3, G3P600, G3P800 | 6 months or 550 gallons |
| CB carbon filter | WD-G3-N3CB | G3, G3P600, G3P800 | 12 months or 1,100 gallons |
| RO membrane (G3P600) | WD-G3P600-RO | G3P600 only | 24 months |
| RO membrane (G3P800) | G3P800 RO cartridge | G3P800 only | 24 months |
| RO membrane (G3) | WD-G3-RO | G3 (WD-G3-W) only | 24 months |
The RO part numbers come from the IAPMO R&T certificate of listing for these systems (file WC-13976), which names each model's certified replacement membrane. The CF and CB are certified for material safety and structural integrity when used in these three systems.
What it costs per year
| Item | Waterdrop list price | How often |
|---|---|---|
| CF pre-filter | about US$30 | twice a year |
| CB carbon filter | about US$30 | once a year |
| G3P600 RO membrane | about US$110 | every two years |
| G3P800 RO membrane | check current price | every two years |
For the G3P600, that comes to about US$90 a year for the CF and CB, plus about US$55 a year if you spread the RO membrane over its two-year life. That matches Waterdrop's own estimate of around US$145 a year. Waterdrop also sells a one-year combo for each model, at around US$90, and autoship subscriptions at a discount.
Prices change with promotions, so treat these as list-price references and check the current price before you buy.
Buying on Amazon
The CF pre-filter and the CF + CB two-pack are also sold on Amazon:
Check that the listing names your model (G3, G3P600 or G3P800) before ordering. Waterdrop also makes G2-series filters that look similar but don't fit G3 systems.
When to change filters early
The intervals assume typical city water. Change earlier if:
- Flow drops noticeably. A clogged CF pre-filter is the usual cause.
- TDS on the faucet display climbs. If TDS rises well above its usual level after a filter change, the RO membrane is the likely culprit.
- Taste or odor returns. That usually points to an exhausted CB carbon filter.
- You're on well water or high-sediment water. Sediment loads the CF much faster. Consider point-of-entry sediment filtration; see our well water testing guide.
How to replace a G3-series filter
- Turn off the water supply to the system and unplug it.
- Open a faucet to release pressure.
- Twist the cartridge counterclockwise and pull it straight out.
- Insert the new cartridge and twist it clockwise until it locks.
- Restore water and power, then flush as the manual instructs. A new RO membrane needs a longer flush than the CF or CB.
- Reset the filter-life indicator for the cartridge you replaced.
Choosing a system?
If you haven't bought yet, the filter costs above are part of the decision. Our Waterdrop G3P600 review and Waterdrop G3P800 review include the full cost of ownership.