Why is a pool pump so important? Because it works with your pool's filtration system to keep the pool clean of debris. The pump pulls water out of the pool through a skimmer basket and then through the filtering system, and back into the pool. Without the pump, nothing works.Most types of pumps will state their capacity, so always know what size your pool is before looking for pool equipment. You should know the basic area of your pool as well as how many gallons it holds. Most pumps will designate how much water they can pump either hourly or by the minute.In most cases, people run a swimming pool pump for six to eight hours a day, especially in the summertime and when the pool is being used. If your pool is small and stays relatively clean, you can cut back that running time in fall and winter months to save electricity.