What Exactly is Total Alkalinity?

Total alkalinity is the total measure of alkaline substances in water and the ability of water to neutralize acid or buffer pH changes. Buffering pH changes refers to how long it will take a quantity of chemical to change the pH level.

It’s bad to have a low total alkalinity, because it means that your pH levels in your pool will fluctuate wildly. If the total alkalinity is too high, pH levels will rise or drift up gradually.

To adjust total alkalinity you should add sodium bicarbonate for increases in TA levels and add sodium bisulfate to decrease TA levels. *Always adjust total alkalinity before adjusting pH!

Ideally you want your pool’s total alkalinity to be between 80-120ppm. For salt water swimming pools you want it between 80-100ppm.

(This is one of our pools where there is some iron in the source water. The pH level drifted up as a result of the chlorine generator producing chlorine and adding a constant increase in pH as well. The pool was treated by lowering the pH and alkalinity, as well as adding a metal removing product, FerriTabs to the water.)

Concerns of low total alkalinity:

  • Etching of plaster, pebble, or grout
  • Corrosion of metal parts, especially copper, stainless steel, and metal on your pool equipment.
  • Staining on the pool’s surfaces
  • Green water
  • burning eyes and itchy skin
  • pH bounce (rapid fluctuations in pH levels)