Quick answer
Test before you dose. At minimum track free chlorine and pH; add total alkalinity and CYA when the water won’t stay balanced. Strips are fine for rhythm; step up to a liquid kit when green, cloudy, or “chlorine won’t hold” shows up.
What each number is for
- Free chlorine (FC): active sanitizer residual.
- pH: comfort and chemical efficiency.
- Total alkalinity (TA): buffer that fights pH bounce.
- Cyanuric acid (CYA): stabilizer — too low and sun eats chlorine; too high and chlorine feels “stuck.”
How to test accurately
Follow strip or kit instructions: depth of sample, wait time, and lighting for color matching. Expired strips lie. Don’t sample right next to a return jet after you just added chemicals.
Common mistakes
- Testing only when the water looks wrong.
- Using expired strips.
- Chasing pH without checking alkalinity.
- Adding chemicals, then retesting five minutes later.
Key takeaways
- Numbers first, products second.
- FC + pH weekly (more in peak heat).
- TA and CYA when balance keeps failing.
- Essentials covers how to choose strips vs liquid kits.