You need to run the pump long enough to generate the chlorine your pool needs. After that, the pump run time is up to your needs to skim the pool surface or other needs.
What FC does your pool consume each day? If you are unsure, use 3 ppm for now. So at 100% generating, the pump must run for 12 hours to generate 2.9 ppm per day. Start there. Test FC each day at the same time of day and if the FC drops, increase your pump run time. If it increases by too much, decrease your % generating or pump run time.