Many pool owners utilize a timer to run the filter system at various times throughout the day. Although running the filter system 24 hours a day is most beneficial for maintaining clean and clear water, running the system at least 12 hours a day will also work. However, if the system is only run for 12 hours, we recommend that it be run during the daylight hours. The 12 hours of operation should be continuous, as starting and stopping the pump motor frequently can have an adverse affect on the motor - necessitating untimely repairs.