Methodology
How we grade and price water.
Every number in the database is meant to be checkable. Here is exactly how the grades, prices, and classifications are produced — and why you can trust that we have no thumb on the scale.
Disclosure grades (A–D)
A water’s grade reflects how much the brand officially discloses about its mineral content — not our opinion of the water, and not whether numbers exist somewhere. A brand that publishes a complete, official analysis earns an A; a brand that publishes nothing but an ingredient list earns a D, even if independent labs have estimated its profile.
| A | Full disclosureThis brand publishes a full numeric mineral analysis, so every value below comes from official data. |
| B | Partial disclosureThis brand publishes some numbers or ranges in official reports, but not a complete analysis — gaps below are the brand's choice, not ours. |
| C | Minimal disclosureThis brand discloses only broad measures like TDS or pH. The mineral-by-mineral picture isn't published. |
| D | No disclosureThis brand lists ingredients at most — no concentrations. You cannot compare what you cannot see; the blanks below are the point. |
Because the grade measures disclosure rather than data availability, a low-grade water can still show mineral values — those come from ingredient lists or independent third-party analyses, and each water’s Provenance line names its source. When you see numbers on a D-grade water, read them as approximate and un-official by definition.
How a water is classified
We classify each water by its chemistry and treatment, not solely by the marketing name on the label. US labeling terms like “spring” and “mineral” are regulated by the FDA but are broad; when a label name and the measured mineral profile disagree, we type the water by its profile and note the label term. For example, a water sold as “Natural Spring Water” whose total dissolved solids and mineral content sit in mineral-water territory is typed Mineral, with its label wording preserved on the detail page.
Where price-per-liter comes from
Price per liter is computed, not editorialized: we record a typical single-unit retail price and the unit size, and the database divides one by the other (price ÷ size in liters). Retail prices vary by store, region, and promotion, so treat price/L as a comparison reference rather than a quote. [PLACEHOLDER — confirm the exact price-sourcing rule (e.g. national retail median vs. MSRP) before launch.]
Verification cadence
Each water carries a last-verified date, shown on its detail page. When a brand republishes its analysis or changes packaging or pricing, we re-check and update the date. [PLACEHOLDER — state the target re-verification interval (e.g. every N months) once finalized.]
Conflicts of interest
h2know sells nothing on its comparison or database pages, and we take no payment from the brands we grade in exchange for coverage or a better grade. Reviews are independent of any product we may offer elsewhere. Where we may eventually sell our own products, we will disclose it plainly and hold those products to the same published standard as everyone else’s.
See the grades in action in the database, or read more about who’s behind h2know.