Water Parameters for Ph and Total Alkalinity:
|pH - Ideal range is 7.4 to 7.6|
|Total Alkalinity - Ideal range is 80-100 ppm.|
The pH is a measure of the active acidity in pool or spa water.
Technically it is a measure of the concentration of hydrogen ions in the
water. The greater the concentration of active hydrogen ions, the lower
On the pH scale from 0 to 14, 7.0 is neutral, less than 7.0 is acidic and
above 7.0 is basic (or alkaline). The range of acceptable pH level in a
pool or spa is from 7.2 to 7.8, but the ideal range is 7.4 to 7.6.
When the pH approaches or goes below 7.2, the water becomes corrosive,
damaging vinyl and plaster surfaces as well as pipes and other equipment.
Low pH can also result in eye irritation for the swimmer.
When the pH goes above 7.6, chlorine disinfectants are less effective in
killing bacteria and algae. The water can become cloudy and scale can form
on the equipment, in sand filters and on the pool walls. High pH can cause
itchy skin and eye discomfort.
|When pH is too high, add acid - Acid combines with water, increases
the hydrogen ion concentration, and lowers the pH. Muriatic acid
(dilute hydrochloric acid - 20º Baume) or Sodium Bisulfate (Dry Acid) are
commonly used to lower the pH. Always follow the label for instruction
on adding acid.|
|When pH is too low, add Sodium Carbonate (Soda Ash) - This is not
the same as Sodium Bicarbonate (Baking Soda). The carbonate ions from
sodium carbonate combine with hydrogen ions to reduce the hydrogen ion
concentration. Sodium Carbonate is available in granular form.|
Total Alkalinity is a measure of the "buffering capacity" of water,
or its ability to resist a change in pH.
The ideal Total Alkalinity level for pool or spa water is 80 - 120 ppm.
When the Total Alkalinity is too low, the pH level can fluctuate widely and the
water can become corrosive. When the Total Alkalinity is too high, the pH
will be high and scale will form on pool surfaces and equipment.
|To lower Total Alkalinity, add Acid - The acid reacts with
bicarbonates in the water and converts them, reducing the Total
Alkalinity. Add 1.6 pounds of Dry Acid (Sodium Bisulfate) per 10,000
gallons of water, or 1.3 quarts of Muriatic Acid, to decrease the Total
Alkalinity by 10 ppm. Retest and adjust the pH.|
|To raise Total Alkalinity, add Sodium Bicarbonate - This adds to
the total bicarbonates in the water, raising the Total Alkalinity. Add
1.5 lbs. Sodium Bicarbonate per 10,000 gallons of water to increase the
Total Alkalinity by 10 ppm.|
Remember, Total Alkalinity and pH level are closely related, so it is
important to test pH after adjusting Total Alkalinity. Likewise, a proper
Total Alkalinity level is important in maintaining the recommended pH
level. It may take several sodium bicarbonate treatments to build the
proper Total Alkalinity buffering level to keep the pH in the proper range.
To Increase Alkalinity using Sodium
VOLUME OF WATER
Desired increase in ppm