Light-dependent reaction. In the light-dependent reaction, light energy from the sun is used to split water (photolysis). which has been taken in by plants. Water, when broken, makes oxygen, hydrogen, and electrons. These electrons move through structures in chloroplasts and by chemiosmosis, make ATP.
Usually, we tell pool owners that between 8 and 12 hours is a good rule of thumb. Many people want to run their pool filter system only at night in order save on electricity during off-peak hours. That's not a bad idea, but it's not the best.
1 Install a timer on your pool pump and run only as long as necessary each day to keep the water clean. In general, run your pool pump eight to 12 hours during the summer. During the winter, only six to eight hours are necessary.  Clean strainer baskets and filters regularly to help your pool pump run more efficiently.