- pH stands for (presence of Hydrogen).
- Numbered from 0 to 14.
- The lower the pH number - the higher Acid.
- That means more Hydrogen Ions (H+).
- The higher the pH - the higher the Base.
- That means less Hydrogen Ions (H+).

- pH is a measure of how acidic/basic water is.
- The range goes from 0 - 14, with 7 being neutral.
- pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base.
- pH is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water.
- Water that has more free hydrogen ions is acidic, whereas water that has more free hydroxyl ions is basic.
- Since pH can be affected by chemicals in the water, pH is an important indicator of water that is changing chemically.
- pH is reported in "logarithmic units".
- Each number represents a 10-fold change in the acidity/basicness of the water.
- Water with a pH of 5 is fifty times more acidic than water having a pH of 6.