Filter cartridges are used in a water filter housing. There are hundreds of different cartridges used for many different water purification and treatment systems. The most common cartridges are sediment cartridges and activated carbon (charcoal) cartridges. Sediment cartridges are used to remove the suspended particles in drinking water while activated carbon cartridges are use to remove dissolved chemicals in water to improve taste and odor. aQuatell carries a broad range of replacement filter cartridges for many treatment applications.