Overview
This lecture covers the importance of pH in pool water, how to test and adjust it, and factors affecting pH balance.
Understanding pH in Pool Water
- pH measures how acidic (low pH) or basic (high pH) your pool water is, on a scale from 0 to 14.
- A pH of 7 is neutral; values below 7 are acidic, above 7 are basic.
Testing pH in Pools
- Check your pool's pH level at least once a week.
- Use electronic pH meters for high accuracy or test kits with indicators like phenol red.
- Kits like the Taylor K2006 offer acid and base demand tests to determine how much chemical to add.
Adjusting pH Levels
- Lower high pH using muriatic acid, dry acid, or pH down products.
- To raise low pH, use borax (raises pH without raising alkalinity) or soda ash (raises both pH and alkalinity).
- Baking soda mainly raises alkalinity, not pH.
Factors Affecting Pool pH
- The type of pool surface impacts acid demand: plaster (cement) pools require more acid, while fiberglass/vinyl pools may need more base.
- Sanitizers influence pH: trichlor tablets lower pH, cal hypo chlorine raises pH, and saltwater generators cause pH to rise over time.
Importance of pH Balance
- Proper pH (7.2–7.4) makes sanitizers more effective at killing bacteria.
- High pH makes sanitizers less effective and slows bacteria elimination.
Relationship Between pH and Alkalinity
- Alkalinity measures how well water resists changes in pH when acids or bases are added.
- pH and alkalinity are closely linked; changes in one often affect the other.
Key Terms & Definitions
- pH — a scale measuring how acidic or basic water is (0–14).
- Alkalinity — the water's ability to resist pH change when acids or bases are added.
- Sanitizer — chemical used to disinfect pool water (e.g., chlorine, cal hypo).
- Acid Demand/Base Demand — the amount of acid or base needed to reach desired pH.
Action Items / Next Steps
- Test your pool's pH weekly using your preferred kit.
- Adjust pH as required using appropriate chemicals.
- Prepare to learn more about alkalinity in the next lecture/video.