Always test your water with a test kit before adding chemicals. Estimates only. CYA dissolves slowly — wait 48–72 hours before retesting. You cannot chemically remove CYA once added.

Pool Stabilizer Calculator (CYA)

Calculate how much cyanuric acid (pool stabilizer or conditioner) to add to protect your chlorine from UV degradation — per SwimUniversity, stabilizer helps chlorine last 3–5 times longer in sunlight. Dosing constant (13 oz per 10,000 gal per 10 ppm) verified against PoolDial (June 2026).

CYA Stabilizer Inputs

Chlorine pool: 30–50 ppm · Salt-water pool: 60–80 ppm

CYA to Add
—
ounces (weight)
Pounds
—
lbs
CYA Raise
—
ppm
Caution: CYA cannot be removed with chemicals — only by dilution (partial drain and refill). Per SwimUniversity stabilizer guidance, add only 70–80% of the calculated dose first. Retest after 48–72 hours and top up if needed. Per SwimUniversity, do not exceed 100 ppm CYA — above this level, chlorine becomes progressively ineffective.

Reference Dosing Table

Pool SizeRaise 10 ppmRaise 20 ppmRaise 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

oz CYA = (Pool gallons ÷ 10,000) × (ppm increase ÷ 10) × 13
  • 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

What is pool stabilizer (CYA)?

Cyanuric acid (CYA), also called pool stabilizer or conditioner, protects chlorine from UV degradation. Without it, UV can destroy half your chlorine in about 17 minutes and leave the pool unprotected within a few hours.

What CYA level should I maintain?

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. Keep free chlorine at roughly 7.5% of your CYA level. Above 100 ppm CYA, chlorine effectiveness drops sharply even if FC readings look normal.

How long does CYA take to dissolve?

Per SwimUniversity, 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.

How do I lower CYA that is too high?

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.

Does CYA build up from stabilized chlorine products?

Yes. Trichlor tablets and dichlor granules both add CYA with every dose — stabilized chlorine products add CYA with each application. Pools that rely on tabs year-round often end up with 100+ ppm CYA by late summer.