Pool, Spa & Water Treatment Chemistry worked example

Cyanuric Acid Adjustment with target cyanuric acid for sanitizer type of 100 ppm: a worked example

What does the result look like when target cyanuric acid for sanitizer type reaches 100 ppm? The full calculation is worked below with real intermediate numbers. Use it before adding stabilizer, choosing sanitizer strategy, or planning dilution.

The inputs for this scenario

  • Target cyanuric acid for sanitizer type: 100 ppm (raised for this scenario; the documented default is 40)
  • Current tested cyanuric acid: 25 ppm (unchanged)
  • Planned stabilizer change from dosing or dilution: 0 ppm (unchanged)
  • Extra CYA reserve above minimum: 0 ppm (unchanged)

Working through the calculation

  • Applying the documented formula (Remaining CYA gap = target CYA - current CYA - planned correction + reserve) to the inputs above produces each figure below.
  • At this operating point the engine returns 75 ppm for remaining cya gap, the number this scenario is built around.
  • At this operating point the engine returns 25 value for current and planned cya.
  • At this operating point the engine returns 100 value for target cya.
  • At this operating point the engine returns 75 % for utilization.

How this compares with the baseline

  • Against the tool's baseline example, where target cyanuric acid for sanitizer type sits at 40 ppm and the headline result is 15 ppm, this scenario comes in 400% above the baseline at 75 ppm.
  • A figure at this level is achievable when target cyanuric acid for sanitizer type is genuinely sustained, not just peaked for a shift. It gives the ppm gap only, not ounces of stabilizer — and CYA can only be lowered by dilution or draining, so a negative gap can't be fixed by adding a chemical.

Results at a glance

  • Remaining CYA gap: 75 ppm (headline result)
  • Current and planned CYA: 25 value
  • Target CYA: 100 value
  • Utilization: 75 %

Run it with your numbers

  • Every input above is editable in the live Cyanuric Acid Adjustment calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.