pH
The measure of hydrogen ion concentration indicating acidity or alkalinity of pool water.
Definition
pH is the scale from 0 to 14 measuring how acidic or alkaline pool water is. A pH of 7.0 is neutral; below 7.0 is acidic; above 7.0 is alkaline. Pool water should be maintained between 7.2 and 7.6. Below 7.2, water is corrosive — it irritates eyes and skin and attacks surfaces and equipment. Above 7.8, chlorine effectiveness drops dramatically (at pH 8.0 only 22% of chlorine is active vs. 67% at pH 7.2) and scale forms. pH is affected by every chemical addition and by CO₂ off-gassing.
Quick Facts
- Ideal Range
- 7.2–7.6 pH
- Units
- pH
- Also Known As
- pH, potential hydrogen, water pH, acidity, alkalinity level
Relationships
Outgoing Relationships
- affected by → Total Alkalinity
- affected by → Temperature
- affected by → Muriatic Acid
- affected by → Soda Ash
- measured by → Water Testing
- calculated by → formula-04
- part of → Langelier Saturation Index
- explained by → glossary/ph
- causes → Low pH
- causes → High pH
- related to → Free Chlorine
- recommended for → Swimming Pool
- recommended for → Hot Tub
Incoming Relationships
- affected by ← Free Chlorine
- related to ← Total Alkalinity
- measured by ← Langelier Saturation Index
- requires ← Water Balancing
- references ← PHTA