Is Clearly Filtered NSF certified?

Last reviewed July 2026.

No — not by an accredited certifier. Not found in the NSF certified listing database (checked 2026-07-13). Clearly Filtered advertises testing to NSF/ANSI protocols by independent labs, which is not the same as being certified by an accredited certifier (NSF, WQA or IAPMO) with ongoing audits.

Why the distinction matters

"Tested to NSF/ANSI 53" and "certified to NSF/ANSI 53" sound identical and are not. Anyone can pay a lab to run a protocol once, on a sample they chose, and publish the result. Certification means an accredited certifier — NSF International, WQA or IAPMO R&T — controls the testing, audits the manufacturing facility on an ongoing basis, and maintains a public listing that anyone can look up. The listing is the point: it is what lets you check the claim without trusting the brand.

This is not an accusation that the filter doesn't work. Independent lab results can be perfectly real, and some uncertified filters test very well. It does mean there is no third-party listing to hold the product to, no ongoing factory audit, and no public record you can consult when the formulation changes.

If you want filters whose claims are in a public database, our ranking only includes NSF-, WQA- or IAPMO-certified models, sorted by cost per gallon of certified filtration.

If Clearly Filtered obtains certification, we'll update this page — the listing always wins. Checked July 2026.

We do not test filters — we index what accredited certifiers publish, with attribution, and make no health or treatment claims. A certification covers a specific model against a specific standard; it is not a general seal of quality. We are not affiliated with NSF International.