How Many Times Does Pool Water Need to Be Turned Over?

Proper Circulation

Proper circulation is imperative to clean, clear and healthy swimming pool water.  It allows the chemicals to mix and work effectively.  It allows dirt and debris to get collected in your filter.  Your filter is the most important stop in your system’s plumbing line.  If all or most of the water doesn’t get through the filter, you are susceptible to murky water, algae and possibly harmful bacteria due to your chemicals not having enough time to effectively sanitize the pool.  

Your water is drawn out of your swimming pool through your skimmer and/or your main drain.  If you have an automatic pool cleaner, water gets sucked up through that.  It is then pushed through your plumbing system.  It goes through your various pieces of equipment you may have such as a salt cell, heater, chlorinator etc.  One thing ALL pools have is a swimming pool filter.  Filters come in three different types: Diatomaceous Earth (DE), Sand or Cartridge.  It is important you run your pool pump enough time to accomplish what are known as turnovers.

What is a Turnover?

A turnover is when all of the water in your swimming pool gets circulated through the filter.  How many times this happens in a 24 hour period is known as a Turnover Rate.  So if all your pool water is circulated twice a day, your turnover rate is 12 hours.  Many things affect your turnover rate such as how long you run your swimming pool pump, the resistance in your system, which is known as total dynamic head, which all play a part in your flow rate. 

How Many Turnovers Does My Swimming Pool Need?

According to the experts, a minimum of 12 hours is recommended.  This means all the water has passed through your filter, being cleaned, 12 hours after the swimming pool pump has been turned on.  Again, this is the minimum.  Most residential pools utilize a turnover rate of 8-10 hours.  Commercial pools can require as little as 6 hours, depending on the county.

How to Calculate Turnover Rate

This can become very complex and you may want to hire a professional to program your swimming pool pump to what is known as your pool’s design flow rate.  This takes into consideration the size of the pool in gallons, the total dynamic head (TDH) and the required gallons per hour.  If you have a flow meter installed in your pool, you can do this yourself.  .

1. Divide the swimming pool shape into areas of constant depth (or constant slopes).  This sometimes means dividing the pool into sections. This is to determine the gallonage of your pool.  If you aren’t looking to get an exact gallonage, you can measure L X W X Average Depth and then multiply it by whatever size the shape of your pool requires.

 A square or rectangular pool is  L x W x D x 7.5 = Gallonage.  A circular, or elliptical pool  would utilize  L x W  x D x 5.9 = Gallonage

2.Turnover Rate (TR)= Gallons divided by Flow Rate (FR) divided by 60.  Flow rate is determined by the measurement on your flow meter. 

You can also utilize your pump’s website or instruction manual to determine the gallons per hour it produces.  It sounds complicated, and it is a bit.

But I Can’t Afford to Run My Pool Pump That Long!

If you are a single speed pump owner, the rule of thumb is to run your pool pump 1 hour for every 10 degrees it is outside.  So if it is 80 degrees, you would run your pump for 8 hours.  We need our pump running when we need our chemicals to work the most, which is the hottest part of the day.  If you are running your pool pump less time, or at night, to “save money” you ultimately aren’t.  The problems you will have in your pool, such as algae, will cost you just the same amount, if not more to correct.

There is a solution!  If you aren’t currently a variable speed pump (VSP) owner, I highly recommend you become one.  Since VSPs run on just that, various speeds ( measured in RPMs), you can run your swimming pool pump for longer at a lower speed, thus saving energy and most importantly…the money on your electric bill.  Variable speed pumps save the homeowner an average of $70 per month.  And they have clean and safe water/

Think you can’t afford a Variable Speed Pump?  Well think again! has several choices of high quality, name brand pumps for about HALF of what you would pay a swimming pool repair store or even a pool guy!  Did you know that the American made , household name of BLACK + DECKER makes a variable speed pump?  Check it out here.

There are really no more excuses not to achieve the proper turnover rate.   Whether we use our swimming pool or not, we still have to have the proper turnover amount.  If we do use our swimming pools, it is not only to keep the water looking good, but safe for the swimmers.  See you poolside!

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How long should the pool pump operate daily, and how should we cut the energy cost of it? Learn here.