Total Alkalinity
What is Total Alkalinity in 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 a change in the pH of pool water.
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:
- pH changes rapidly when chemicals or impurities enter the water
- pH may drop rapidly, causing corrosion etc.
If total alkalinity is too high:
- pH becomes difficult to adjust.
- High pH often occurs causing other problems such as; cloudy water, decreased disinfectant effectiveness, scale formation and filter problems.
Controlling 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.