Are all carbon filters equally effective?
No. Activated carbon filters are usually rated by the size of particles they are able to remove, and generally range from 20 microns down to 0.5 microns (most effective). The two most important factors affecting the efficiency of activated carbon filtration are the amount of activated carbon in the unit and the amount of time the contaminant spends in contact with it. The more carbon the better. Particle size also affects contaminant removal rates. The most common carbon types used in water filtration are bituminous, wood, and coconut shell carbons. While the coconut shell carbon is typically 20% more in cost, it is by far the best of the three.
