calcs.homes
calcs.homes
Enter your current and target free chlorine level and pick your product to find exactly how much to add.
Estimate only — add at dusk to reduce UV loss, and retest after circulating.
Each product's dosing constant reflects its available chlorine concentration — weaker products need more volume to deliver the same ppm increase. Liquid chlorine at 10% needs about 10.1 fl oz per 10,000 gallons per 1 ppm, 12.5% needs about 8.1 fl oz, and 65% cal-hypo granular needs about 2 oz by weight.
1-3 ppm for most pools, though pools with higher stabilizer (CYA) levels may need 3-5 ppm to sanitize as effectively — check the Free Chlorine / CYA ratio if algae keeps coming back.
Different chlorine products carry different concentrations of available chlorine — a weaker 10% liquid needs more volume than a stronger 12.5% liquid to deliver the same ppm boost.