"Activated carbon filters are generally employed in the process of removing organic compounds and/or extracting free chlorine from water, thereby making the water suitable for discharge or use in manufacturing processes. Eliminating organics in potable water, such as humic and fulvic acid, prevents chlorine in the water from chemically reacting with the acids and forming trihalomethanes, a class of known carcinogens. Activated Carbon (AC) filtration, as with any water treatment method, is not capable of removing every possible type of contaminant. For example, sodium, microbes, fluoride, and nitrates cannot be removed with AC filtration. Water softening also cannot be achieved with AC filters. In addition, heavy metals, such as lead, can only be removed with a very specific kind of activated carbon water treatment, which is typically used only in residential point-of-use filters."

1: NGMA - 20

2: NGMA - 30

3: NGMA- 45

4: NGMA- 65