[From French p(ouvoir) h(ydrogene) lit. hydrogen power.]
So let’s start looking at chemistry from the simplest point of view.
What is pH? It is the quantity of Hydrogen in a solution, or the concentrations of H+ (hydrogen) in a solution.
Unlike most scales which are linear scales; For example, difference between 1.0, 2.0 and 3.0 all have equal distances or quantities of 10 divisions.
The pH Scale is a logarithmic scale, in other words, the difference between pH 1 & pH 2 is 10; and the difference between pH 1 & pH 3 is 100. Example: There is ten trillion times more hydrogen in pH 1 than there is in pH 14.
In the below chart it show the difference between:
In other words pH 1 has ten trillion times more hydrogen than pH 14. Or pH 14 has (1x 10 to negative 14 power) (1x 10 –14[WK1] ) less hydrogen.
So for a soil pH to change from a high pH of 8 down to a pH of 5 it is not a factor of 3, but because the pH Scale is a logarithmic scale, it is a factor of 1000. Therefor one has to add 1000 times more acid to bring down the pH. In other words one has to add 1000 times more H+.
Difference between 5 pH and 6 pH is 10
Difference between 5 pH and 7 pH is 100
Difference between 5 pH and 8 pH is 1000
Winston W. J. Kao 727-447-2344 or email@example.com