Chlorine, on contact with the carbon, chemically alters into the harmless compound called chloride. Carbon filters have expansive surface areas with these exchange sites and are remarkable at removing standard chlorine from water supplies. Chloramines, however, have unique stability as a compound. Upon contact with activated carbon, they are not catalyzed with the same efficiency and speed. In order for activated carbon to remove chloramines, very extensive contact time is required to successfully break the ammonia and chlorine apart. This makes them a poor choice for chloramine reduction, as you could not run a shower or fill a bath with such reduced flow rates. Since skin sensitivity is one of the primary reasons people eliminate chloramines, a filtration system capable of sustaining at least a moderate flow rate is crucial for success.
