How Long Should I Run My Pool Pump in Winter

We all know the importance of circulation and filtration of a swimming pool.  The hotter it is, the more we need the water to circulate.  What about during the Winter, or at least, colder, months?  

Why is Circulation Important?

In order to have a clear pool, we need to move the water.  Think of a stagnant pond.  It is green and murky.  Now think of a running stream.  The water in the stream tends to be clear.  This is from the constant “flowing”.  We need our swimming pool water to also flow.  This is done by your swimming pool pump pushing the water through your system.  It makes many stops along the way depending on what kind of equipment set-up you have.  You may have a salt system.  You may have a heater.  You may have an auto-dispense system or an in-line or out of line tablet feeder.  One thing is for sure.  We all have one thing in common: a pool filter.  This is the most important stop in having a clean, inviting pool.

Did you know the sanitizer only works effectively when the water is moving?  When do we need our sanitizer most? During the hottest part of the day.  People who choose to run their pump at night to “save money” are actually doing themselves a disservice.  They are more prone to algae blooms and may end up spending what they “saved”, or more, on chemicals to combat the algae.  Not to mention the most precious thing:  their time. 

Single Speed Pumps

Most of my customers who opt to still run their swimming pool pump at night are typically owners of what is known as a single speed pool pump.  This sort of pump only runs at one speed.  3,500 RPMs ( Revolutions Per Minute).  These “energy guzzlers” as I like to call them cost a fortune to run.  Unfortunately, when we need our pool pump the most is sometimes when the department of energy has the higher tiers.  This is one of the many reasons to invest in a variable speed pump.  Even 2-speed pumps only save you a bit of money on the lower speed.  But in order to get the proper filtration, you will need to incorporate a period of high speed.  The rule of thumb for a single speed pool pump owner is one hour for every 10 degrees outside.  If it is 40 degrees outside, that would equal 4 hours.  If it is 100 degrees outside, that would be 10 hours!  

Variable Speed Pool Pumps

Variable speed pool pumps are also known as energy efficient pumps.  This is because they can be run at a variety of speeds.  On the highest setting of 3,400 RPMs, which you wouldn’t really need unless you needed the power for the jets in your hot tub, variable speed pumps are still more efficient.

As far as the length of time you need to run your variable speed pool pumps depends.  There are multiple different ways to run them.  They all utilize a combination of “higher” and “lower” speeds to achieve what is known as a turnover.  A turnover is getting all the pool water through the filter.  Some of my customers run their pumps on a lower setting for 24-hours a day.  Most of my customers have a combination of low, medium and high speeds.  The lower the speed, the longer you have to run it.  This is because even though we have upgraded to an energy efficient pump, our pool gallonage hasn’t changed.  We still need to get all the water through the filter at least once.  Twice in the hot months if possible.

I usually recommend a combination of speeds.  A high setting, somewhere in the high 2,000s for an hour or two.  This will get your automatic pool filter running, if you have one, and move a lot of your pool water through your system.  Then I suggest a medium RPM setting for 3-4 hours.  This can be mid 2,000.  Keep in mind certain pieces of equipment require a certain flow to operate.  These can include a salt system, automatic pool cleaner and even the heater.  So, for example, if you were going to put the pool into spa mode, you would be asking the pump to run on a higher RPM.  Then I suggest a very low RPM, apx around 1,700 RPMs for several hours..  This is just to keep the water moving, thus keeping the chemicals active.  Your salt system will not produce during this time and your automatic pool cleaner may stop completely or come to a crawl.  This is ok because we have already accomplished our needs from these pieces of equipment when we were running our variable speed pump at the higher speeds.

The point is the lower we have our speed set, the longer we have to run our pump.  You can have whomever installs your pump to program it based on your pools' specifically needed flow rate.  This is called a design flow rate. This takes into consideration the resistance in your plumbing known as total dynamic head.

But Variable Speed Pumps Are Too Expensive

This is the most common reason that my customers stay with the older technology of a single speed pump.  A variable speed pump saves you money on your electric bill.  On average, around $70 a month.  Could be more or less depending on your region.  An energy efficient pump is one of the few things we can invest in that actually pays us back!

Variable speed pumps don’t have to break the bank. has several affordable VSPs (variable speed pumps) to choose from.  My personal favorite is the American made and household name of Black and DeckerIf you were to look for a similar pump from other name brands like Pentair or Hayward, you would literally be paying double.  

It doesn’t matter if you have a single speed pump or a variable speed pump, running it long enough is a major component in having a clear and algae free pool.  In states like California, having a variable speed swimming pool pump is required by law.  Even if it isn’t, why on earth would you want to pass on those energy savings?  See you poolside!


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