Alkalinity – Adjusting
Adjusting Total Alkalinity (TA) Levels
Adjusting the Total Alkalinity is something that should be done incrementally. In other words, it is better to make slight adjustments when the TA gets a little high or low than to wait for the TA to get way off and try to adjust it all back at once.
If the TA is way off, we recommend making an adjustment and then retesting it after 24 hours and adjusting again.
To raise the TA level (and not the pH too), you add Baking Soda (Sodium Bicarbonate). Baking Soda will also raise the pH of the pool water slightly. If you need to raise both the pH and TA, then use Soda Ash until the pH comes to the proper level, then use Baking Soda to make further adjustments to the TA if needed. NOTE: Soda Ash (Sodium Carbonate) and Baking Soda (Sodium Bicarbonate) are NOT the same thing.
To lower the TA level, you add Muriatic Acid. It is important that if you want to lower the TA without significantly lowering the pH, you need to pour the acid in the pool directly in one pint shots in the deep end. By creating pockets of extremely low pH temporarily, you will burn off the alkaline materials in those areas, thus bringing down the Total Alkalinity reading of the pool.
Chemical Adjustment Charts
It is important to use the Acid or Base Demand Procedure to help determine how much chemical you need to add to the pool water to achieve the desired results.
To Raise the TA Level
Check the chart to see how much baking soda is needed to raise the TA level as desired. Do not attempt to raise it more than about 50 ppm at one time. If the TA is at or below 50 ppm, be sure to test for metals in solution before adding Soda Ash or Baking Soda to the pool.
Adding Baking Soda to a Pool
Slurry the baking soda in a bucket and pour the dissolved solution into the pool.
To Lower the TA Level
Check the chart to see how much acid is required to drop the TA in your pool to the proper level. Do not add more than one quart of acid per 10,000 gallons at one time. If more acid than this is needed, then make one adjustment, then retest before making another adjustment. As always if your readings don’t make sense, seek the advice of a professional.
Adding Muriatic Acid to Lower TA Level
Add the Muriatic Acid to the pool in one pint shots in the deep end. Brush the pool afterwards to insure that the acid does not drop down to the bottom and etch the surface since acid is heavier than water.
BEWARE OF THE DANGEROUS NATURE OF THE CHEMICALS YOU ARE HANDLING. DO NOT MIX ANY CHEMICALS WITH EACH OTHER. WATCH OUT FOR FUMES. SOME CHEMICALS GIVE OFF STRONG FUMES THAT CAN CAUSE SERIOUS PERSONAL INJURY IF INHALED IN SUFFICIENT QUANTITIES. MSDS SHEETS ARE AVAILABLE UPON REQUEST.