Activated carbon filters are mainly used to remove chlorine and organic compounds from water. The operating system is the same as that of sand filters, carrying out the retention of contaminants by passing the water through a filtered bed made up of activated carbon.

Pleated filters are made of layers of microfibers that make up a fine or thick pleat. In them, the largest particles tend to settle on the surface of the filter material, while the finest ones settle in the filter matrix. They also have a larger surface where the retention process of undesirable particles occurs thanks to multiple layers that are obtained by the folds of the filter material. There are two retention principles of pleated filters: first, mechanical entrapment, where the sediment particles hit the fibers of the filtering element and remain detained, and second, absorption, where a physical and chemical phenomenon occurs where the particles are attracted to the interior of the microfiber.

Los principios de retención de los filtros plisados son dos, primero el de atrapamiento mecánico, en donde las partículas de sedimentos impactan con las fibras del elemento filtrante y quedan detenidas, y segundo, el de absorción en donde ocurre un fenómeno físico y químico donde las partículas son atraídas hacia el interior de la microfibra.