Pool Care Dictionary
Algae -
microscopic forms of plants that grow in the water and cause discoloration.
Algaecides -
chemicals that prevent and control algae growth.
Bacteria -
microscopic organisms (germs) that can cause illness.
Chelating Agents
- chemicals that combine with dissolved metals to prevent water discoloration
and stains.
Chlorine - the
most commonly used disinfecting agent for swimming pools.
Chlorine Demand -
the amount of chlorine needed to destroy bacteria, algae, chloramines, and other
swimming pool contaminants.The chlorine demand must be satisfied before a
chlorine residual is available to disinfect the pool water.
Chlorine Residual
- the chlorine level in the water after the chlorine demand has been satisfied.
The free available chlorine is the true measure of chlorine disinfection.
DPD - an
indicator tablet used to measure the free available chlorine residual. Turns red
pink in presence of chlorine.
Dry Acid (Sodium Bisulfate)
- a granular material used to lower the presence of chlorine.
Free Available Chlorine
- that portion of the total chlorine remaining in chlorinated water that is not
combined with ammonia or nitrogen compounds and will not react chemically with
undesirable or pathogenic organisms.
Hardness - The
amount of calcium or magnesium dissolved in the water. High levels may
contribute to scale deposits.Low levels may lead to corrosion and etching of
plaster pools.
Hypochlorous Acid
- The most powerful disinfecting form of chlorine in water.
Muriatic Acid - a liquid used for lowering pH or total alkalinity.
pH - Measurement
of the acidity / alkalinity of water. Readings above 7 are alkaline: readings
below 7 are acidic.
ppm - parts per
million. Example: one penny in $10,000 equals 1 ppm.
Phenol Red - the
indicator solution that measures pH.
Scale - a
precipitate that forms on surfaces in contact with water when the pH level,
Total Alkalinity and/or Calcium Hardness are too high.
Shock Treatment -
the addition of 5-10 ppm of free available chlorine, in response to a particular
pool problem such as algae.
Stabilizer - (Cyanuric
Acid or conditioner) (s-triazinetrione), also called Isocyanuric Acid. A
chemical that helps prolong the useful life of chlorine in the water by slowing
down chlorine decay due to sunlight.
Total Alkalinity
- Acts as a buffer to prevent changes in pH.
Total Chlorine -
The sum of free available chlorine and combined chlorine.