CYA Added from Tabs

How the CYA Added from Tabs Estimator Works

Trichlor tablets add chlorine and cyanuric acid at the same time. This estimator uses the pool volume and the number of standard 8-ounce tablets used to estimate how much CYA may have accumulated.

The estimate is useful for seeing how quickly stabilizer can build when tablets are used regularly. It does not replace an actual CYA test.

Why CYA Builds Up

The chlorine from a trichlor tablet is consumed as it sanitizes the water, but the cyanuric acid remains behind. Every new tablet adds more stabilizer unless water is removed through backwashing, splash-out, leaks, or draining.

Why High CYA Matters

CYA protects chlorine from sunlight, but too much CYA makes chlorine less effective at the same Free Chlorine reading. As CYA rises, the pool needs a higher FC level to stay properly sanitized.

Common Tablet Mistakes

• Using tablets all season without testing CYA.
• Assuming tablets add only chlorine.
• Keeping the same FC target while CYA rises.
• Using tablets in a feeder year-round without tracking buildup.
• Waiting until algae appears before checking stabilizer.

Frequently Asked Questions

Do all trichlor tablets add CYA?

Yes. Trichlor contains cyanuric acid, so every tablet adds stabilizer as it dissolves.

Can CYA be removed with chemicals?

In most residential pools, the dependable way to lower CYA is partial drain and refill.

Should I stop using tablets completely?

Not necessarily. Tablets can be useful for vacations and slow chlorination. The key is testing CYA and avoiding uncontrolled buildup.

How often should I test CYA?

Test during the swimming season and any time a significant number of tablets have been used.