Pool Chemical Calculator
PoolScan is a free pool chemical calculator. Enter your test readings — or photograph your test strip and let AI read them — and it tells you exactly how much of each chemical to add, in the right order, based on your pool volume.
How it works
- 1Enter your pool volume — or estimate it from your pool's dimensions with the volume calculator.
- 2Enter your test readings, or scan your test strip and review what the AI detects.
- 3Get exact doses for each chemical, sorted into the correct treatment order, with safety notes and swim-wait times.
What it calculates
High CYA and high calcium cannot be lowered chemically — the calculator tells you when a partial drain and refill is needed instead.
The maths behind it
Every dose comes from published pool chemistry, cross-checked against PoolMath (Trouble Free Pool) and Orenda Technologies. A worked example: raising free chlorine by 1 ppm in a 10,000-gallon pool takes about 12.8 fl oz of 10% liquid chlorine. A 20,000-gallon pool needs double; a 2 ppm rise needs double again.
The calculator also handles the interactions that simple dose charts miss:
- •pH doses are adjusted for your alkalinity — the same acid dose moves pH further in low-TA water.
- •Shock targets are based on your CYA level, not a fixed number — high stabiliser needs more chlorine to sanitise.
- •Large doses are split into stages with retest reminders, so you never overshoot.
Treatment order matters
Doses are sorted into the industry-standard sequence: alkalinity → pH → chlorine → stabiliser → calcium. Alkalinity buffers pH, and pH controls how effective chlorine is — so fixing them out of order means chasing your own tail. If both alkalinity and pH need treatment, the calculator tells you to wait between them.
Common questions
How much chlorine should I add?
Roughly 12.8 fl oz of 10% liquid chlorine per 1 ppm rise per 10,000 gallons — but the right dose depends on your volume, reading, and CYA. Enter your numbers and the calculator does the rest.
Do I need to know my pool volume?
Yes — every dose scales with water volume. If you don't know yours, estimate it from length, width, and average depth in about 30 seconds.
Is it really free?
Yes — no account, no app install, no paywall. The site is funded by Amazon affiliate links on product suggestions.
Enter your readings and pool volume — get exact doses for every chemical, in the right order.
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