How we test, verify, and make money
Most review sites hide the incentives. We publish ours, because a recommendation you can't audit isn't a recommendation; it's an ad.
How we evaluate systems
We rank water treatment hardware on measurable specifications: rated grain capacity, service flow rate at realistic pressure drops, regeneration strategy (metered beats calendar), iron tolerance, and warranty terms. Where we cite a spec, it comes from the manufacturer's documentation or an independent listing, never from marketing copy, and every product row in our database carries a link to its source.
Certified vs. claimed
A manufacturer saying "NSF certified" and actually being listed in the NSF public database are different things. We check every certification claim against that database and mark each one as certified (linked to the listing) or claimed (manufacturer statement only). We re-check on every content refresh.
Sizing math you can check
Our sizing calculator uses the standard industry formula: household size × daily gallons × compensated hardness × days between regenerations, plus a stated safety margin. The formula, constants, and their sources are documented on the calculator page itself. If a plumber's quote disagrees with our math, you'll know exactly which assumption differs.
Where our data comes from
- Utility Consumer Confidence Reports for city hardness figures
- The NSF/ANSI public listings for certification status
- Manufacturer spec sheets for performance claims
- Live price APIs for current pricing
Every figure links to its source and carries a "last verified" date. Stale data is worse than no data, so dates are always visible.
How we make money
HomeWaterPure is reader-supported. When you buy through outbound links marked on this site, we may earn a commission from the seller. Commissions never change rankings: comparison order is computed from verified specs before any commercial factor enters. We don't accept payment for placement, we don't sell physical products, and no brand previews our conclusions before publication.
Outbound affiliate links route through our own redirect (/go/…) so we can count clicks. That record is also how we notice when a merchant's real-world experience stops matching their promised terms.
Keeping pages honest over time
Prices refresh via API; certifications and city data get re-verified on a schedule; and when we change a recommendation, the page notes what changed. If you find an error, it has one author who fixes it: write to corrections@homewaterpure.com.