Total Alkalinity

Total alkalinity is a measure of the total amount of dissolved particles in the water whose pH is higher than 7.0. Total Alkalinity (TA) should usually be kept at 80 - 120 ppm, though in high alkalinity waters this is often hard to achieve without resulting in an abnormally low pH. When your TA is low, the following can occur:

  • etching of the plaster, marbelite, marcite or tile grouting

  • corrosion of metal parts (pool heater, steps, scoop pole, etc.)

  • staining of the pool's surfaces

  • green water

  • burning eyes and itchy skin

  • pH bounce (rapid fluctuations in pH)

What is alkalinity?

Raising Low Total Alkalinity

Sodium bicarbonate (bicarb) will raise the TA without excessively raising the pH. You should try to increase the TA over a period of time, adding a maximum of 1 pound of bicarb for each 6,000 gallons of water.  When the TA is too high, the following can occur:

  • pH keeps going up despite regular addition of pH-down

  • cloudy water

  • burning eyes and itchy skin

  • reduced chlorine efficiency resulting in algae growth

Lowering High Total Alkalinity

To lower a high TA, you should:

  • turn off the pumps and allowing the water to settle

  • slowly add the pH-reducer into one spot in the deep end of the pool

  • allow the chemicals to "burn off" some of the alkalinity for 15 - 30 minutes 

  • turn the pumps back on and allow the water to mix thoroughly