Chlorine Tablet Dispensing

• Chlorine tablets in the most highly concentrated form, with 90 percent chlorine, do not immediately dissolve in water. Because of their low rate of solubility in water (1.2 percent), putting a chlorine tablet into the bottom of the pool to treat the water results in a tablet sitting there days later. Chlorine tablets must have a dispenser to allow for the proper dispersal of the chemicals into the pool water as they dissolve. This prevents the wrong amount of chlorine from entering into the water.
  
  

Chlorine in Water

• As chlorine dissolves in the water, a chemical reaction occurs, changing the chlorine into hyperchlorous acid. This acts to kill living organisms (algae and bacteria) in the water. Left to grow, these organisms would cloud the water and potentially cause water-borne illnesses in those who swim in the pool.
  
  The chlorine that does not get used to kill organisms in the pool water becomes free chlorine. This floats through the pool water maintaining the clarity and continuing to sanitize the water. Should ammonia, urea or other nitrogen-based compounds also be in the pool water, combined with the free chlorine, they produce combined chlorine residual. This binds the chlorine that no longer has sanitizing capabilities.
  
  Adding more chlorine to the water (shocking) interacts with the nitrogen-based compounds to remove them from the water when the chlorine evaporates in the sun. Over time, chlorine tablet treatments need repeating because all free chlorine eventually converts into a gaseous form in sunlight and evaporates from the pool.
  
  

Effects of Chlorine Tablets in Water

• Direct contact with a chlorine tablet can bleach the interior of the pool. Homeowners often forget that chlorine tablets act as concentrated discs of bleach, removing color from pool surfaces. Use a specially made chlorine dispenser to preventing discoloration. Dispensers also prevent corrosion damage to water circulation systems that can occur by leaving a chlorine tablet in a skimmer basket.
  
  To prevent over or under chlorination of water, pool owners should check the water chemistry of their pools on a weekly basis by using an over-the-counter pool chemistry test kit.