Combined Chlorine (CC) in Pool Water

Combined Chlorine (CC) refers to chlorine in pool water that has reacted with organic contaminants, such as sweat, oils, and ammonia, forming chloramines. Unlike free chlorine, combined chlorine is less effective as a sanitizer and causes unpleasant odors and irritation.

How Combined Chlorine Forms

  • Reaction with Organics: Free chlorine reacts with organic matter introduced by swimmers or the environment.
  • Ammonia and Nitrogen Compounds: Chlorine binds with these compounds to form chloramines.

Why Combined Chlorine is a Problem

  • Reduced Sanitization: Combined chlorine is less effective at killing bacteria and viruses.
  • Strong Odors: Chloramines are responsible for the "chlorine smell" often associated with poorly maintained pools.
  • Irritation: Causes eye, skin, and respiratory discomfort for swimmers.

How to Test for Combined Chlorine

  1. Use a Test Kit: Measure free chlorine and total chlorine levels.
  2. Calculate Combined Chlorine: Subtract free chlorine from total chlorine to find the combined chlorine level.

How to Remove Combined Chlorine

  1. Perform Breakpoint Chlorination: Add enough chlorine to reach 10 times the combined chlorine level.
  2. Improve Circulation: Run the pool pump continuously to distribute chlorine evenly.
  3. Shock the Pool Regularly: Prevent combined chlorine buildup with regular maintenance.

Prevention Tips

  • Maintain proper free chlorine levels at all times.
  • Encourage swimmers to shower before entering the pool to minimize organic contaminants.
  • Use a pool cover to reduce debris and environmental contamination.

Related Terms

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