Activated carbon filters are small pieces of carbon, in granular or block form, that have been treated to be extremely porous. Just one gram of activated carbon has a surface area of 500-3000m2 (600 to 3600 sq yards). 4 grams is the equivalent of a football field. It’s the massive surface area that allows active carbon filters to be very effective in adsorbing (essentially removing) contaminants and other substances.
In addition to the surface area active carbon filters have different capabilities in terms of the size of contaminants they remove. Activated carbon filters range from around 50 microns to 0.5 microns.The smaller the more effective but smaller pores also may reduce water flow.
When the water flows through active carbon filters the chemicals stick to the carbon resulting in purer water output. The effectiveness depends on the flow and temperature of the water. Therefore most smaller active carbon filters should be used with low pressure and cold water.
Activated carbon is usually made of coconut shells, wood or coal and sold as granular activated carbon or carbon blocks.
