Free tools
Pool calculators for operators
US units, real chemistry, no sign-up. Built for the pool deck.
61.4 fl oz
of 12.5 % liquid chlorine raises free chlorine by 2 ppm in 30,000 gallons.
How much liquid chlorine raises free chlorine by 1 ppm?
About 10.2 fl oz of 12.5 % liquid chlorine per 10,000 gallons. The calculator handles 10 % and 12.5 % liquid, cal-hypo, dichlor and trichlor, and warns about the CYA or calcium they add.
What is breakpoint chlorination?
Raising free chlorine to about 10 times the combined chlorine (total minus free) to destroy chloramines. Enter free and total chlorine: the calculator gives the target and the dose.
Why does the acid dose depend on alkalinity and CYA?
Because carbonate and cyanurate buffer the water: the same pH drop needs more acid at 120 ppm alkalinity than at 80. The calculator solves the buffer instead of using a fixed rule of thumb.