Diatomaceous filtration ensures perfect results: clear water, filtered with a fineness that do not equal Filterregulators sand. Traditionally, diatom filters are known for their delicate maintenance. The diatomaceous filter system Hayward we placed in lieu of extremely old Culligan installation is very reasonable in maintenance requirements and, provided, they are replaced filters (7 + 1 polypropylene filter to inside the tank) from time to time not to be compelled to do every week against a backwash, satisfaction is with go. Based on our experience of two years of an outdoor pool 100m3, we suggest replacing the filters after two seasons.