Affiliate disclosure
None of the product links on this site are affiliate links yet. If we add them, buying through one may earn us a commission at no extra cost to you, and this page explains the rules they follow.
How we choose products
A product is listed only if we can confirm its certification for the specific contaminants we match it to, from the certifying body's listing or the manufacturer's performance data sheet. Marketing claims aren't enough.
Commission doesn't decide what we list. A product without a verified certification doesn't appear, whatever it pays. A product with a verified certification can appear even if we earn nothing from it.
Certifications change. The products listed now were last checked in November 2026, against the document linked next to each one. When we find that a certification no longer covers what we say it does, we remove the product.
What affiliate links don't affect
Water quality data, town pages and the limits we compare against come from utility reports and government records. They aren't influenced by any company.