Quick Answer
What Is Total Alkalinity in a Pool and How Is It Adjusted?
Total alkalinity is a buffer value that shows the water's resistance to pH swings, with an ideal range of 80–120 ppm. Low alkalinity causes pH to fluctuate rapidly, while high alkalinity makes it difficult to move pH into the target range. It is raised with sodium bicarbonate and lowered with acid.
Ideal Alkalinity
80 – 120 ppm
The Relationship Between Alkalinity and pH
Alkalinity acts as a pH 'buffer': when it's in the correct range, pH stays stable despite chemical additions or bather load. When alkalinity is low ('pH bounce'), water chemistry readings vary daily and dosing becomes unreliable.
For this reason, correction order matters: alkalinity should be balanced first, then pH, and finally chlorine.