What Should Cyanuric Acid Levels Be in a Pool?
Cyanuric acid is measured in parts per million and the appropriate target depends on the pool, climate and sanitation approach. The important rule is to test accurately and follow guidance that matches your equipment and sanitizer system.
If CYA is below the recommended range for your pool, chlorine can be lost rapidly to sunlight. If it is too high, the usual correction often involves dilution rather than adding another chemical.
Use test results—not a calendar—to decide whether stabilizer is needed. Read What Is Pool Stabilizer? for the basics.