1.33 oz of cyanuric acid per 10,000 gallons raises CYA by 1 ppm — and the only way down is draining water. Both directions, calculated below.
Add 79.8 oz (4.99 lb) of cyanuric acid
Raises CYA from 0 to 40 ppm in 15,000 gallons. Add slowly via skimmer sock or dissolved in a bucket — solid stabilizer takes days to fully register on tests, so retest in 3-5 days before adding more.
This calculator gives you today's number. The app remembers your pool.
CYA sets your chlorine target for the whole season. Poolably saves your pool's volume and history, builds the full treatment plan in the right order, and reminds you when to retest — free on iPhone.
Get Poolably freeChlorine, pH, and alkalinity all move both ways with chemicals. CYA only goes up — every dichlor puck and stabilizer scoop accumulates for the season. That is why the target matters: your CYA sets your chlorine requirement all summer (see how the CYA-chlorine relationship works, then check your dose on the chlorine calculator). Testing methodology matters too — CYA is the least precise home test; the test strips guide covers reading it right.