Pool alkalinity is one of the many factors that affect the water quality of your swimming pool. Total alkalinity is closely related to pH, measuring the pool's ability to neutralize acids. In the proper range of 80 ppm to 150 ppm, total alkalinity keeps the pH level stable.
If the total alkalinity is too low, then the pH can fluctuate wildly at the slightest addition of an acid or base. The pH often drops randomly, causing damage to metal fixtures, etching of the pool walls, staining of the pool walls, and swimmers to get stinging eyes and itchy skin.
If the total alkalinity is too high, it becomes extremely difficult to change the pH. In this situation, the pH is often too high, making the water cloudy, building upscale on the walls of your pool, and your chlorine becomes ineffective as a sanitizing agent. Your tests will also specify that the pool is in constant need of acid. Application of acid to the pool is the means of decreasing total alkalinity, but the process can take weeks and is best supervised by an experience pool caretaker.
Check your total alkalinity regularly, but in a well-maintained pool, there should be little fluctuation.