How We Verify Specs

The rules

• Every spec has a source. Each unit in the database stores the manufacturer or authorized-retailer page it was read from and the date we read it. That source is linked on the unit's page.
• Empty beats guessed. If a manufacturer doesn't publish a number, the field shows “—”. We never fill gaps from third-party reviews or memory.
• Rated beats marketed. Where manuals give rated capacity at each salt dose, we record it. The “40,000 grain” on the box is usually the maximum-salt-dose figure, and the unit notes say so.
• Certified means certified. The certifications field lists only standards stated on the source page (e.g. NSF/ANSI 44). “Independently tested” is not a certification and is recorded as a note, not a cert.
• Commercial and editorial claims never merge. If a unit is ever promoted for commercial reasons it will be labeled as such. That label will never imply its specs were verified more deeply than others. A spec source and check date can't be bought.

What this doesn't claim

We haven't lab-tested these units, and prices, checked on the dates shown, change with promotions (several direct-to-consumer brands run near-permanent “sales”, and where a strike-through MSRP looked like marketing, the unit notes say so). Found an error? Tell us and we'll fix it against the source.