Pool Stabilizer Calculator (CYA)
Calculate how much cyanuric acid (pool stabilizer or conditioner) to add to protect your chlorine from UV degradation. Dosing constant (13 oz per 10,000 gal per 10 ppm) verified against PoolDial and SwimUniversity (June 2026).
CYA Stabilizer Inputs
Chlorine pool: 30–50 ppm · Salt-water pool: 60–80 ppm
Reference Dosing Table
| Pool Size | Raise 10 ppm | Raise 20 ppm | Raise 40 ppm |
|---|
Constant: 13 oz (0.81 lbs) granular cyanuric acid per 10,000 gal per 10 ppm increase. Source: PoolDial CYA calculator; SwimUniversity — verified June 2026.
Formula
- 13 oz — ounces of granular CYA that raises 10,000 gal by 10 ppm (industry constant)
- ppm increase ÷ 10 — scales with desired rise
- Pool gallons ÷ 10,000 — scales to pool size
Related calculators: Salt Calculator · Shock Calculator · Chlorine Calculator · Alkalinity Calculator
Frequently Asked Questions
Cyanuric acid (CYA), also called pool stabilizer or conditioner, protects chlorine from UV degradation. Without it, summer sunlight can destroy a pool's entire chlorine supply in 2–3 hours.
For conventional chlorine pools: 30–50 ppm. For salt-water (SWG) pools: 60–80 ppm, as the constant chlorine generation benefits from more UV protection. Above 100 ppm, chlorine effectiveness drops sharply even if FC readings look normal.
Granular cyanuric acid typically takes 48–72 hours to fully dissolve, especially in cooler water. Use the sock method (fill a nylon sock with granules, hang it in front of a return jet) or pre-dissolve in warm water. Always wait at least 48 hours before retesting.
There is no chemical that removes CYA from pool water. The only way to lower it is dilution — partially drain the pool and refill with fresh water. Calculate the percentage to drain: (Current CYA − Target CYA) ÷ Current CYA.
Yes. Trichlor tablets and dichlor granules both add CYA with every dose — roughly 6 ppm per pound of trichlor per 10,000 gal. Pools that rely on tabs year-round often end up with 100+ ppm CYA by late summer.