If you are going to spend several hundred dollars on a new pump, and then several hundred dollars more every year in electrical costs, doesn't it make sense to get one that is sized properly and won't waste energy? 

 Manufacturers build a wide variety of pumps to meet the varying demands of all kinds of pools, spas and water features.

Getting the right pump can save you money and get the best performance out of your system.

FLOW RATING (GPM)

A pump should be able to "turn over" the water in a home pool in 8 hours.  In other words, it should be able to pump the entire capacity of the pool in that time.  If you have a 16,000 gallon pool and want a turnover rate of 8 hours, the pump would need to be able to move 2000 gallons per hour, or 33 gallons per minute.  

Once you know the GPM rating you are looking for, you can then look at the pump comparison chart and click on the pumps that are best suited to your needs.

But what about the HORSEPOWER rating?

Unfortunately the horsepower ratings on pumps have gotten very confusing, ever since the manufacturers began to "uprate" pumps.  In other words, the exact same pump that would normally be considered a 1.5 HP full rated pump is now often sold as a 2.0 HP uprated pump.

SERVICE FACTOR (SF)

The service factor on a pump motor can best be described as "power to spare."  The service factor times the horsepower rating equals the actual horsepower rating of the motor.  In other words a 2.0 HP pump with a 1.25 service factor, actually has a 2.5 hp motor on it.  A 2.0 HP pump with a 1.0 service factor has a 2.0 hp motor on it. 

Here is the bottom line as far as service factor.  A higher service factor will make the pump less likely to overload and overheat.  A higher service factor will also generally mean that the pump has more power as compared to the same pump with a low service factor.

HIGH HEAD OR MEDIUM HEAD?

Pumps can be classified as either high or medium head.  The head rating of a pump basically refers to how much the flow is reduced in the face of resistance.  You could also say that it refers to how well the pump handles under pressure.

A high head pump will see less reduction in flow in the face of resistance.  In other words, if the pool filter needs backwashing, the flow will not be reduced as much as if you had a medium head pump.  On circular grid DE filters, a high head pump can create pressures high enough to ruin the filter grids if you do not backwash in time.

A medium head pump will create more flow on average, but will see more reduction in flow in the face of resistance.  This creates great efficiency for water transfer pumps where there is not a lot of resistance to flow.  It is also useful on pools with circular grid DE filters so that you do not risk damaging the grids due to high pressure.

High head pumps are normally recommended for most pool applications, HOWEVER, if you have a vertical curved grid DE filter (except for Sta-Rite), you may want to consider a medium head pump such as Sta-Rite Dyna Glas or Pac Fab Whisperflo

ENERGY EFFICIENCY

Most people do not even stop to think about the cost or running an inefficient pump, but it is an important concern.  So you save $50.00 on a pump, then you spend $150.00 each year in additional electric bills for the next ten years.  Hmmm . . . sounds like a no brainer.

Lets compare a typical 2.0 HP pump, regular model vs energy efficient model.