The Zodiac CS 150 pool cartridge filter is loaded with appropriate filter material (which can be sand, glass or other material). The debris and impurities are thus retained in the filter body. A high-performance filtration system is essential for the effectiveness of water treatment. The filter is very compact and can also be installed in small technical rooms. Filtration is ultra fine up to 15-20 microns for crystal clear water. No need to be connected to the drain.