CC is combined chlorine, also called chloramine. It is the waste product of the chlorine oxidation process and is not desirable to have. It causes the harsh chlorine smell associated with pool, and can irritate sensitive skin and eyes. It is an important number to know as a CC of 1.0 or more indicates a problem that requires more chlorine to resolve. CC is constantly being created and broken down, so it is not unusual to see 0.0 to 0.5 levels at any given time. Higher levels of CC indicate the FC is working on oxidizing some organic waste out of the pool.
Use PoolMath to determine what your correct FC level should be according to your test results.
Use PoolMath to determine what your correct FC level should be according to your test results.