Swimming Pool Terminology

Following are some of the common terminology used in the pool service industry and what they mean.

Acid - Chemical used to lower total alkalinity and pH. The most common liquid form is muriatic acid. Also available in granular form (Sodium Bisulfate).
Algae - Aquatic plant life that will grow in pool water. The most common variety is green algae.
Alkalinity - the measure of your pool water's ability to resist change in pH.
Alkalinity Booster - Chemical used to raise total alkalinity (Sodium Bicarbonate).
Bacteria - Microscopic organisms that may be present in inadequately sanitized water. May be unhealthy condition for swimmers.
Chlorine - Most common chemical used for protecting pool water from bacteria and algae. Common forms are stabilized and unstabilized.
Chlorine Stabilizer - Chemical used to help prevent loss of chlorine due to exposure to sunlight (Cyanuric Acid).
Combined Chlorine - (Chloramines) - Chlorine that is combined with waste matter in pool water that renders the chlorine ineffective to prevent bacteria and algae growth. Usually causes a chlorine odor and eye irritation.
Free Chlorine - The most active chlorine in pool water to prevent bacteria and algae growth. Total chlorine less combined chlorine equals free chlorine.
pH - A measurement of the alkalinity or acidity of water.
pH Bounce - A condition when pH is unstable. Usually indicates a need to correct total alkalinity before making any other correction.
Shock Treatment - The practice of quickly raising chlorine levels for the purpose of releasing combined chlorine (Super Chlorination).
Soda Ash - Chemical used to raise pH.
Stabilized Chlorine - Chlorine that when used in stabilized pool water best provides long-term chlorination.
Total Chlorine - the sum of combined chlorine and free chlorine.
Unstabilized Chlorine - Chlorine that when used in pool water provides fast acting short-term chlorination.