Is It Better To Run Your Pool Pump At Night Or 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.Click to see full answer. In respect to this, is it OK to run pool pump 24 hours a day?there should be no reason you HAVE to run 24 hours. if you have a variable speed pump on low, then running 24 hours is no big deal because its not costing much. running a single speed pump all day is gonna get expensive.One may also ask, should pool pump run continuously? Although it’s generally recommended that all the pool water undergo filtration every 24 hours, the pump does not need to run all the time. If your pool is in constant use, you may need to run the pump for up to eight hours per day, frequently checking the water clarity and chemical balance. Then, how many hours a day should you run your pool pump? 8 hours Can you run pool pump with cover on?1 Answer. Sure, a pool cover doesn’t bother the works at all. Most outdoor hot tubs are designed to have a cover over them while waiting for bathers to show up. If there are any aerators, I would close them if it will be running for more than a few days without the cover being removed—to keep it looking nice and smooth