Remove the cartridge from the filter housing or skimmer box.
Wash the filter using a garden hose working from the top down.
Soak the cartridge for at least an hour (overnight is preferable) in a cartridge cleaning solution which you can purchase from your local Spa & Pool shop.
Rinse the cartridge once more with a hose to remove any remaining oils or cleaning solution
Eventually your cartridge filter will block and will need to be replaced - usually within 1 to 2 years - depending on the amount of use.
All cartridge filters should be cleaned at least every 2 months.
If you follow the normal cleaning procedures you will ensure the maximum life of the cartridge