What is Alkalinity:

Total alkalinity is closely associated with pH but rather than a measure of hydrogen ion concentration it is a measure of the ability of a solution to neutralize hydrogen ions. Expressed in parts per million (ppm), total alkalinity is the result of alkaline materials including carbonates, bicarbonates and hydroxides - mostly bicarbonates.

This acid neutralizing (buffering) capacity of water is desirable because it helps prevent wide variations in pH whenever small amounts of acid or alkali are added to the pool. Total alkalinity is a measure of water's resistance to change in pH. More simply – alkalinity in the proper range helps to eliminate large swings in the pool water pH.

Adding Sodium Bicarbonate to Increase Alkalinity:

Whenever we add acid to the pool it decreases the alkalinity – we remedy this by adding sodium bicarbonate (bicarb) directly to the pool. The Pump Room Operator is responsible for maintaining the alkalinity by adding bicarb. 

Adding bicarb should be done when there are NO swimmers present in the pool. The best way to add is directly to the pool. The acid feed pumps should be turned off while you add the bicarb and should remain off for a minimum of 45 minutes after you have finished adding the desired amount of bicarb.