About

About What Filter Removes

What Filter Removes is an independent reference that answers two questions well: does this water filter really remove what I'm worried about, and what will it cost me to run? It checks 102 popular US filters against certifier listings for 18 contaminants and computes running costs with one published formula.

What we do and don't do

• We look up every reduction claim in the certifiers' public databases (NSF, WQA, IAPMO R&T, CSA) and link the listing next to it.
• We report claims a brand makes from its own lab tests separately, labelled "brand test only".
• We take specs and replacement-filter prices from each brand's own store and link the source.
• We don't lab-test filters ourselves, we don't give medical advice, and we don't accept payment for placement or rankings.

How the site is funded

Some "Check price" links are affiliate links. If you buy through one, the store may pay us a commission at no extra cost to you. Every filter gets the same formula, and rankings follow published rules, whether or not a brand has an affiliate program with us.

Corrections

Listings change: certifiers add and withdraw claims, and brands rename models. If something here is wrong or out of date, let us know and we'll check it against the listing and fix it.