Terms of use
Plain terms for a free information site. Using HotTubCalc means you accept these.
Information and estimates only
The calculators and guides on this site are general information and estimates, not professional, medical, or safety advice. Dosing figures are starting estimates computed from published chemistry; water, products, and equipment vary. Always follow the directions and warnings on your chemical product labels, which take precedence over anything here. Add chemicals in small steps, never mix them, and retest before adding more.
No warranty and limit of liability
The site is provided as is, without warranty of any kind. We do our best to keep the math correct and check it when the site is built, but we do not guarantee any result, and we are not liable for any loss, injury, or damage arising from use of the site or reliance on its figures. You are responsible for handling pool and spa chemicals safely and for your own equipment.
Affiliate links
Some outbound links are affiliate links, including Amazon. As an Amazon Associate this site earns from qualifying purchases. These links cost you nothing extra and do not change the information or recommendations on the page. See the privacy page for how analytics work.
Changes
We may update these terms or the site at any time. Last updated 2026-06-13.