pH ("Potential Hydrogen") is a measure of acidity/alkalinity ranging from 0-14.0. While a pH of 7.0 is considered neutral, our blood has a pH of around 7.4. The standard for domestic water is 6.5 - 8.5. A pH of 7.0, is often considered to taste the best. However, the taste also depends on personal preference and can vary according to the water and purity or mineral content levels.