The cartridge filter is an important type of Swimming pool filtration plant pool in India. These filters are so named as they have a pleated spun polyester filter cartridge that looks similar to the air filter which you will get in your car. Water is forced via the cartridge pleats and it will trap dust and debris as small as 5-25 microns, an important improvement over sand filters. Cartridge filters need very low maintenance. An over-sized cartridge filter only requires to be cleaned about every 6 months, or when the filter pressure is 8-10 psi over the standard reading.