Hot tub water, balanced.
Tell the dosing calculator your gallons and your test reading, and it tells you exactly how much to add. Plus plain-English guides for the day the water goes cloudy, foamy, or off. Built for chlorine and bromine alike.
Free, no account Works offline We do not sell you chemicals
Calculators
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How it works
- Find your water volume once, with the volume calculator or your tub's spec. We remember it.
- Test the water. Balance alkalinity first, then pH, then sanitizer.
- Enter a reading and a target on the dosing calculator, add the amount shown in small steps, and retest.
Every dose is computed from published chemistry and checked against its source when the site is built. No invented numbers.
Find your hot tub's size
Look up the water capacity, dimensions, and full weight of popular hot tub and inflatable models, from Jacuzzi and Hot Spring to Intex and Coleman SaluSpa. Your gallons drive every chemical dose, and each model page links straight into the dosing calculator.
Thinking about an inflatable?
The inflatable hot tub guide covers running costs, capacity, and how blow-up tubs compare to hard-side, then points you to the water-care basics that keep any tub clean.