Figuring out filter reqs. with pump running on low speed


In The Industry
Jun 2, 2007
Annandale, VA
I'm looking at a new filter. All the charts in terms of size correlate to the filter size, how many hours the pump is on, and water turnover. So, say a given filter can process 29k gallons of water in 8 hours and I have a 24k gallon pool. What if I run my pump on low speed? Will I have to leave it running 2x as long? I understand that running filters at a lower gpm setting lets them do a better job, I just don't know how this impacts my pump run time.


TFP Expert
Apr 29, 2016
Quaker Hill, CT
You only need to run your pump as long as it takes for the water to stay skimmed, stay heated, or long enough for your SWG to generate enough chlorine. The concept of turnover is a little outdated. In reality it only takes about 20-30 min for the pool water to mix enough with the pump running to blend all the chemicals on a daily basis.

Since you have a SWG the pump run time will likely be based on how long your cell needs to make enough chlorine. Even at lower speeds that will likely be enough to keep your water clean. If you want to run it longer to keep the surface skimmed that is up to you and won't hurt anything.