What is free chlorine?
Free chlorine is the name given to hypochlorous acid or hypochlorite ion in basic solution. It is the most effective form of chlorine sanitizer.

What are chloramines?
Chloramines are the products of the reaction of free chlorine (hypochlorous acid) and ammonia or organic amines. Some chloramines are sanitizers but they are less effective than free chlorine.

What is Total Chlorine?
This is the name given to the total amount of free chlorine and chloramines in a water sample. If the amount of total chlorine is greater than that of free chlorine, there are chloramines present in the sample.