can a pool pump run at night instead of day
The Sun is one of them, and you are giving it free access if you run it at night. It may be cheaper to run the pump at night, but honestly you should run it 1 hour a day per 10 degrees of temperature, and it should be during the day. Running the pump at night should only be when you are doing a major chemical treatment such as algae clean-up. Your pool is more vulnerable during the day, plants don't grow at night the way they do during the day--that's true of ALL plants including Algae.
I was told by the pool guys that I should run the pumps during the hottest time of the day. I was reading in another post that electricity service is cheaper at night so that is why they run the pumps at night. I live in TX so you know it is hot down here.