When to Run the Pump


Apr 24, 2008
I was unable to find a thread specific to the following question so if it has been addressed already my apologies.

When is the correct time of the day or night to introduce FC?

The two schools of though that seem to prevail are.
1) Run the pump during the day to combat the FC loss due to sunlight.
2) Run the pump at night to maximize FC efficiency.

Are there any variables that need to be considered?


Mod Squad
TFP Expert
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LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
Are there any variables that need to be considered?

My suggestion would be to run the pump when it works best for you.

Do run it enough so your all your pool water passes thru ("turns over") thru at least twice daily and three causes no harm. For most folks, that's around 8-12 hours daily. Many folks split that run time into two or three periods.....I like that idea as well but that's your call.

Adjust the time accordingly as you get more and more familiar with your pool.

BTW, Welcome to the forum!! :lol: :lol:


Well-known member
May 20, 2007
Houston, Tx
personally, I add the FC at night, about 5-6 if I can, just as the sun has passed completely over the pool. I run the pump 1-2 hr after adding the chemicals. I then run my pump on a daily basis from 11am-5pm (the heat of the day) to keep water moving to reduce evaporation and have the chlorine affecting all of the water, so to prevent the bloom of algae.

duraleigh said:
Many folks split that run time into two or three periods.....I like that idea as well but that's your call.
when I told my father in law I did that, he freaked out and said it was better to run all at one time, "he's been told". but what does he know, he still uses trichlor and told me that bleach was bad for pools....


TFP Expert
LifeTime Supporter
May 30, 2007
South Carolina
Hi Clearblue and Welcome to TFP.

Variables. Yep.

We have found that our pool stays perfect w/ 6 to 8 hours run time per day, split between morn and eve.

Also, we add our bleach as soon as the sun is off the pool and make sure to give at least an hour run time to insure a good mix.


Well-known member
Sep 19, 2007
I run my filter 24/7. Probably overkill but we heat the water with a heat pump and right now it needs to run to get water to the heater. I may cut it back to about 18 hours a day when the water will stay warm in July/August. Also I think the filter has to be on for my slide and 3 deck jets to run. Anytime we are in the pool the kids always want these on. My Polaris won't run without the filter on either, some kind of programming interlock with my controls.


In The Industry
Mar 22, 2008
Depends on how you add your chlorine to the pool... Do you have a salt chlorine generator, add bleach by hand, chemical erosion feeder, etc.? I would definitely be getting some chlorine into your pool during the day. Most, if not all, of the chlorine added overnight will burn off during the day without CYA. I have all of my clients pools running 9am-9pm unless they have an automatic cover they leave on most of the day.