First, check the pool for wear or damage. Repair or replace broken equipment and fill cracks well before the first freeze. Vacuum the pool and clean all surfaces. Check the water chemistry, balancing for pH, alkalinity and calcium hardness. If necessary, treat with winterizing chemicals.
Lower the water level according to the type of cover used. Or drain the pool completely, if the facility is built for this and hydrostatic conditions do not exist. Drain and blow the water from all pipes, then add antifreeze and plug the lines. Drain as much water as possible from the heater and filter. Any valves that cannot be drained or filled with antifreeze should be taped with electric heat tape.
All handrails, ladders and diving boards should be removed, cleaned thoroughly and stored in a dry location. Remove underwater light fixtures from their housing, and secure them to pool bottom. Turn off the circuit breaker to the lights and motors.
Drain the pump and add pump lubricant or antifreeze. Coat the drain-hole threads of cast iron pumps with lubricant. Disconnect the power to the pump motor and remove the motor. Follow manufacturers instructions for winterizing filters.
Secure the pools cover to keep out debris and water. This is also a good time to check other safety measures, such as fencing, for necessary repairs.