What is Total Alkalinity in Swimming Pool water?

 Total alkalinity is closely associated with pH but 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. 

Total alkalinity is a measure of water's resistance to change in pH

It should be maintained in the range between 80 and 150 ppm. If total alkalinity is too low:

If total alkalinity is too high: 

How to Control Total Alkalinity

Total alkalinity can be raised by the addition of soda ash (sodium bicarbonate, baking soda)  - there are other proprietary products on the market that are even more effective - just follow the instructions on dosage.

Total alkalinity can be lowered by adding muriatic acid (hydrochloric acid) or sodium bisulfate or other proprietry products. Just remember your pool water will only be OK if the pH is right - and that will depend on total alkalinity.