About & Methodology
What this site is
FilterWise HQ publishes independent buyer's guides to whole-house water filtration for US homeowners. We are reader-supported: when you buy through links on our site, we may earn an affiliate commission at no extra cost to you. See our affiliate disclosure.
How we compare systems
Most "best filter" lists rank by whoever pays the highest commission. We rank by three verifiable inputs:
- Manufacturer-published specifications — flow rate (GPM), capacity (gallons), media type and stages, replacement intervals, warranty terms. Every number on this site traces to a spec sheet or manual.
- Independent certification listings — NSF/ANSI 42 (aesthetic effects), 53 (health effects), P473 (PFOA/PFOS), 61 (material safety), 58 (reverse osmosis), via NSF or IAPMO listings. We distinguish "certified to" from "tested to."
- 10-year ownership cost — purchase price plus the published maintenance schedule over a decade. This is the number that actually separates a $600 system from a $1,100 one.
What we don't do
- We do not claim laboratory testing we did not perform. When we cite test data, we name the lab or listing.
- We do not publish prices as facts — prices change constantly, so every button says "check current price."
- We do not recommend systems for water chemistry we have not addressed — well-water buyers, start with a water test.
Corrections
Specs change and we can get things wrong. If you spot an error, emailcontact@filterwisehq.com and we will verify and correct it.
Not medical advice
Our guides are for information only. For health questions about your water, consult your water utility and qualified professionals — and test your water.