Version 1.0 · September 2026
A ranking should leave an audit trail.
Our scores begin with contaminant fit and exact-model evidence. Affiliate availability never adds points, and a famous brand cannot compensate for an undocumented claim.
100-point model
How the score is built
Category weights remain fixed within a published ranking. Product-specific exceptions and missing evidence are recorded.
Contaminant fit
The system addresses a documented need, not a generic fear.
Independent verification
Certification listings and performance sheets match the exact model.
Ten-year cost
Equipment, replacement media, consumables, water use, and required service.
Household fit
Service flow, pressure loss, capacity, footprint, and installation demands.
Terms and support
Warranty exclusions, returns, replacement access, and useful support.
Gate 01
We verify the exact model.
Names shared across several sizes or generations are not treated as one product. We record the model identifier, performance data sheet, certification listing, media or membrane specification, rated flow, capacity, replacement schedule, warranty, and current price.
Gate 02
We separate certification from marketing language.
“Certified,” “tested by,” “tested to,” and “uses certified components” are different claims. We look for the exact model in an accredited certification body’s listing and record the specific reduction claims. Certification to NSF/ANSI 53, for example, does not mean a filter reduces every contaminant addressed anywhere within that standard.
Gate 03
We calculate ownership—not checkout—cost.
Our cost record includes the system, required prefilters, replacement cartridges or media, salt or other consumables, expected membrane replacement, water used for regeneration or concentrate, and manufacturer-required service. Installation is shown separately when site conditions make a universal estimate unreliable.
Gate 04
We state what we actually did.
A documentation review is labeled as such. Physical installation, flow testing, water sampling, teardown, support calls, and long-term use are only claimed when performed and documented. Manufacturer-supplied samples do not receive favorable scoring.
Gate 05
We preserve the downside.
Every ranked product includes a “do not buy if” condition. A system can score well for one water profile and be the wrong choice for another. We do not convert a conditional recommendation into a universal winner.
Commercial independence
Money is disclosed. It is not scored.
Water Filter Report may earn a commission when a reader uses certain links. Commercial availability does not determine eligibility, placement, score, or the language of a review.
If the best-supported option has no affiliate program, it can still rank first. If an affiliate partner fails an evidence gate, it can be excluded.
Read the affiliate disclosure →