Sand filters should be cleaned at least once per season, preferably in the fall before closing. You must clean your sand filter after encountering bouts of algae.
It is much easier to clean your filter media at the end of the season rather than waiting until the beginning of the season. If all the dirt and oil has had time to settle over the winter it can cause calcification resulting in the need to change the media. Cleaning your sand should be done at least 24 hours before closing the pool.
Enter your postal code to check your area.