Total Alkalinity (T.A.)
This is not to be confused with the pH alkaline level, they are two separate things but they are very much related to each other for maintaining a correct water balance.
T.A. (Total Alkalinity) is a measure of the “buffering capacity” of water, or its ability to resist changes in the pH levels.
*The ideal T.A. level for your Pool or Spa / Hot Tub water is 80 – 120 ppm*
When the T.A. is too low the pH level can bounce up and down rapidly and the water can become corrosive.
When the T.A. is too high, the pH will be high and scale will form on your Swimming Pool surfaces.
To Lower T.A.: add Dry Acid (pH Minus), this reacts with the bicarbonates in the water and alters them which will then reduce the T.A. You will need to add about 0.725 kg of Sodium Bi-sulphate or 0.590 kg of Muriatic Acid per 10.000 gallons of water; this dosage will reduce the T.A. by 10 ppm.
To Raise T.A.: add Sodium Bicarbonate (T.A. Plus), this increases the total bicarbonates in the water therefore raising the level. Dose with 0.680 kg of Sodium Bicarbonate per 10.000 gallons of water; this will raise the T.A. by 10 ppm.
Remember, T.A. and pH are closely related so it is important that you test pH after altering T.A. Likewise, a proper T.A. level is paramount in maintaining the correct pH level. It may take a few treatments to reach the correct T.A. buffering level to keep the pH in the optimum range but is worth every second spent on it as with an incorrect T.A. level you are going to drive yourself crazy all summer wondering why you can’t get the pH balance right in your Swimming Pool.