What is pH?

• April 5, 2024 |

The letters ‘pH’ stand for potential of hydrogen, and pH is a measure of the concentration of hydrogen ions in the water, which indicates how acidic or basic a solution is. The pH range goes from 0 to 14; see Figure 1.0 on page 4 for an illustration of this scale. Values less than 7 indicate acidity, and values greater than 7 indicate basicity/alkalinity. Examples of acidic liquids include stomach fluid (pH between 1 to 3.5), lemon juice (pH of 2.4), and vinegar (pH of 2.8). An example of a basic liquid is bleach (pH of 13.5). The pH of drinking water depends on the water source, treatment methods, and other factors, but generally lies within the range of 6.5-8.5.