Along with the acid/base demand charts in the back of the booklet that came with your kit, you can use the acid/base demand tests to figure out how much acid or base you need to add to get to a certain pH. If your pH is high, then you add the acid demand reagent dropwise to your pH test (after you've read the pH with the indicator dye already added) where you will see that each drop makes the pH test color move lower in pH. When you get to the pH you want, you look in the booklet and look in the table using the number of drops you added and your pool size and you'll see how much acid to add.
The same principle applies to the base demand test, but in the opposite direction when your pH is too low and you want to raise it.
Another use for these acid/base reagents is to move the pH up or down in the pH test to more clearly see what the pH level is. Sometimes it's hard to read the colors until one gets used to it.
