About Water Filter Nerd

Water Filter Nerd is an independent review index for water filters, built around the certification, not the marketing. A pitcher, an under sink system, and a whole house filter all make the same promise. Few can prove it. We start at the NSF listing and work outward.

Every product in the index is scored on the same seven verifiable criteria: certified removal scope, certification and test transparency, filter life, cost per gallon, flow rate, install and footprint, and maintenance burden. The result is the Nerd Stamp™, a 1 to 7 rating with a public methodology.

We do not test products. No lab, no borrowed units, no sample bottles. Every review is a spec breakdown built from manufacturer documentation, NSF and WQA certification records, and published third party performance reports, held against the claims on the box. When a maker will not publish a certification number, the review says so and the score reflects it.

We accept no free products, hold no manufacturer relationships, and sell no placements. The site is funded by Amazon affiliate commissions, disclosed on every page and in full at our affiliate disclosure. A filter cannot buy its score. A brand cannot buy its position.

Corrections policy: if a published specification is wrong, we correct it and update the revision date on the page. Specifications are sourced from manufacturer documentation, NSF and WQA certification listings, and published performance reports.