We are going to skip many of the technical details since it is not really necessary that a pond keeper knows exactly what pH is. What is important is to know how to make pH measurements, to routinely make the measurements, and how to interpret their results. The discussion below is not intended for chemistry majors nor for anyone who desires a technically accurate description of our subjects. It is provided for the average pond owner to visualize what is going on in his or her pond.
Various substances exhibit similar characteristics in how they react with other substances.
A broad range of these characteristics has been divided into the two categories, acid and base, where the pH measurement is related to a ratio of the base components to the acid components. If a substance has one acid component for each base component, it is said to be neutral and has a pH value of 7. Greater than 7 is less acid, more base, and less than 7 is more acid and less base. Each unit is 10 times the previous, i.e., a pH of 9 is 10 times more base than 8, a pH of 5 is 10 times more acid than 6. Some examples of more acid like things are vinegar, orange juice, and the liquid in your car battery that makes holes in your clothes.