How Long Should I Run My Pool Pump?

The above question is posed to the likes of me (pool industry folk) on a regular basis. Actually strike that – I impose the answer to that question on homeowners every day because I am tired of seeing them throw away good money.  A pump does not need to run 24/7 to keep your pool water pristine. If properly sized, a pump should spin through your water in a fraction of the time, allowing it to be dormant for the rest of the day. Thereby, relieving your wallet of the heavy burden of high electric bills.

Well, What Is the Answer, Smart Guy?

Residential pool water only needs to be turned over once daily to have proper filtration.  Twice through the filter may be necessary after heavy usage such as a pool party. Only commercial pools require water to be turned several times a day to maintain proper sanitation. Anything more than a 1-2 filter cycles in a day is superfluous, almost as superfluous as someone using the word superfluous.

The key to a properly sanitized pool is not only filtered water but also well-balanced water chemistry. If your water is unbalanced then issues will arise no matter how much the water churns. A good once through your filter system should alleviate you of troublesome bacteria barring some kind of major chemical imbalance.

How Do I Calculate a Filtering Cycle?

With a few measurements and some math (oh no!) we can assess our proper pump run time.  Before we begin we will need a few things: overall dimensions of your pool including length, width, and depths (shallow and deep ends), the model number of your pump, and a rough estimate of the length of pipe to your pool (feet of head.)

Calculating Pool Gallons

To know how long to filter, we need to know how much we are filtering.  For this step, we will be using a trick of trade called the Pool Volume Calculator by Penair.  This easy to use calculator provides your pool gallonage in a few keystrokes. No complex volume formulas for this guy.

For our example, we will say our pool is a total of 24,000 gallons.

Pumping for Information

Now we must determine the approximate water flow produced by our pump. For this we must know the model number of the pump and the feet of head of the pool. Again, the feet of head is the average length of pipe leading from the pool’s skimmers and main drain to your pump.

For our example, I have chosen a Hayward Super Pump 1.5 HP Single Speed, model number SP2610X15. And for our imaginary pool the length of pipe to the main drain is 20 feet and the pipe feeding the skimmer at the other end of the pool is 60 feet, totaling an average of 40 feet of head.

Feet of Head Calculation:

20 Feet +  60 Feet = 80 Feet

80 Feet ÷ 2 Pipelines = 40 Feet of Head

Using the model number SP2610X15 and calculated feet of head on the below chart we can see that the approximate rate of flow is 65 gallons per minute (GPM.)

And then…..  

The hard part is done but we still have 2 more calculations to complete to determine the run time for one filtering cycle of our pool. Using the numbers we deduced from previous calculations we use:

24,000 Gallon Pool ÷ 65 GPM Flow Rate = 369 minutes for full-cycle

369 minutes ÷ 60 Minutes = 6.15 Hours for Filtering Cycle

And there is the answer,  6.15 hours filtering time will cycle your water once.  This equation can be applied to any pool and adjusted for any run time. We normally suggest having a run time of 6-12 hours for filter cycles.

As usual, if after reading our blog posts more questions arise or there is a further explanation needed, do not hesitate to call our techs at 877-372-6038.