Filter Ledger is a source-linked foundation for buying the right water-filter replacement. Updated October 1, 2026.
Foundation | Records | Costs | Methodology | Disclosure | For agents | llms.txt
Systems
Exact models only. A similar name does not establish fit. Prices are not shown where unverified, and hardware prices are unknown, not zero.
| Brand | Model | Name | Status |
|---|---|---|---|
| Brita | OB41 | Pacifica | manufacturer model verified; price pending |
| Brita | OB63 | Tidal | manufacturer model verified; price pending |
| Waterdrop | WD-10UA | Direct connect | variant price and registry pending |
Replacement cartridges
| Model | Months | Gallons | Condition |
|---|---|---|---|
| Brita OB06 | 6 | 120 | hard water can need earlier change; manufacturer max 2 gal/day |
| Waterdrop WD-RF10 | 12 | 11000 | capacity applies to chlorine reduction; local water affects life |
| Waterdrop WD-RF15 | 24 | 19000 | capacity applies to chlorine reduction; local water affects life |
| Waterdrop WD-RF17 | 36 | 24000 | capacity applies to chlorine reduction; local water affects life |
| Culligan UNRESOLVED | None | None | replace at TDS 6 or higher per manufacturer; not a contaminant safety test |
All values are manufacturer-reported. Capacity depends on local water.
Fit relationships
| System | Cartridge | Relation | Limits |
|---|---|---|---|
| Brita OB41 | OB06 | compatible | Certified claims must be exact pair-specific |
| Brita OB63 | OB06 | compatible | Certified claims must be exact pair-specific |
| Waterdrop UA/UB/UC | RF10/RF15/RF17 | manufacturer states compatible | Exact selected SKU and certification still need verification |
| Legacy ZeroWater pitchers/dispensers | New Culligan ZeroWater cartridge | incompatible | Manufacturer explicit warning; do not mix generations |
Certification claims
Not yet public-eligible. Both claims below come from the manufacturer’s own sheet. Registry verification is pending permission from the certifier, so neither is shown as verified.
| Pair | Contaminant | Standard | Status |
|---|---|---|---|
| brita-ob41 + brita-ob06 | Lead | NSF/ANSI 53 | manufacturer_reported |
| brita-ob63 + brita-ob06 | Lead | NSF/ANSI 53 | manufacturer_reported |
Working name. No original testing, payment or affiliate enrollment. The $1,000 monthly profit target is a goal, not a forecast.