How we build our tools
Each tool does one job you would otherwise do with a manual, a label and a calculator. The numbers inside them come from published sources: PHTA (the Pool and Hot Tub Alliance) dose tables, EPA-registered product labels, the CDC’s water ranges and the makers’ own manuals for error codes. Every result shows where its number came from.
- Pool chemical calculator: works out your gallons, then how much chlorine, baking soda, acid, calcium, stabilizer or salt to add.
- Hot tub chemical calculator: the same math scaled to a few hundred gallons, with a bromine option.
- Error code lookup: codes for inflatable hot tubs, Balboa and Gecko spa packs, and Hayward, Pentair, Jandy, Raypak and AquaCal heaters and heat pumps.
The tools are free and work in your browser. They do not replace your product label or your equipment manual, and when the two disagree, follow the label.