How we check the numbers
Every figure on this site traces to a source, and most are re-checked automatically each time the site is built. If a check fails, the build fails and nothing ships. Nothing ever goes live half-verified.
Dosing chemistry, checked at build time
The dosing calculator is not a copied chart: it computes each amount from published water-chemistry rates, and the build script runs 17 explicit assertions against the cited references before any page is generated. That means, for example, the total alkalinity math must come out to 24 oz of sodium bicarbonate for a 10 ppm rise in 10,000 gallons — within rounding — or the build stops with the failing line printed.
The references the constants are calibrated against:
- Taylor Technologies dosage tables · the standard pool and spa water-chemistry dosage reference the dosing constants are calibrated against
- PoolMath (Trouble Free Pool) · the public pool and spa dosing calculator the constants are cross-checked with
- Pool & Hot Tub Alliance (PHTA) · the industry association whose balanced-water guidance sets the target ranges
Dosing data last verified 2026-08-08.
Model specs, traced to saved sources
Every capacity, dimension, and weight in the size database comes from a manufacturer spec sheet, product page, or archived brochure, and each model page says where its numbers came from. The library holds 215 saved source pages, so when a figure is questioned there is a copy of the original to check it against rather than a memory of one.
When something is wrong
Email contact@hottubcalc.com with the page and the number. It is checked against the source above, and if it does not hold up the figure is corrected and the change is recorded on the corrections log.