Pool Pump


Before you can select the correct filter for your pool, you must first select the correct pump for your pool. Your pool filter must be matched to your pool pump. For instance, if the filter is too small relative to the pump. the pump will generate more water pressure in the filter than the filter is able to handle. This imbalance will quickly break down the filtering material of the filter and that will diminish the effectiveness of the filter.

We recommend that you be able to filter all that water in your pool twice a day. Most pool owners require a pump/filter system that will recycle their pool water every 8 hr.

1) calculate the total gallons in your pool.

2) calculate the Gallons Per Minute (GPM) required to filter 

Pool Size Gallons Gallons/Hour Gallons/Minute
15 x 30 18,500 2300 39
16 x32 21,000 2625 44
18 x 36 27,000 3375 56
20 x 40 33,000 4125 69
Calculate Gallons Per Minute Required To Filter

3) Determine Feet of Head – As water flows through the system piping between the pool and the pump, it will meet with resistance to flow according to factors like the length of the piping, the number of turns (elbows) and the diameter of the piping. This resistance is called “Feet of Head or “Head”. As Head increases, your pools’ actual GPM will decrease.

Pump Size Feet Of Head  
  30ft 40ft Over 40ft
½  hp 45 GPM 29 GPM Will not run
¾ hp 58 47 30 GPM or less
1.0 hp 76 65 50 GPM or less
1.5 hp 90 80 65 GPM or less
Determine Feet of Head


Go to the description page of the style of pump you would like to purchase. Many pump manufacturers will provide a chart on this description page showing the HP required for your particular GPM and Foot of Head requirement. For example, say you wanted a pool pump that will handle 44 GPM with a 45 Feet of Head. According to the chart, we need a pump 1 HP (50 GPM).


The size of your pool filter is directly related to the pool pump you have selected. If your pool filter is too small for the pump, there will be additional strain on the pump motor as it tries to push water through and meets resistance at the filter. This will eventually burn out the pump motor and your filtration will also be compromised. We recommend over-sizing the filter to be absolutely certain it can handle the flow coming from the pump. So in this case, instead of getting a filter rated at exactly 44 GPM, you should select one that is a little higher – around 60 GPM would be fine.


The size of your system is mostly determined by the size of your above ground pool. The gallons found inside your pool will give you the horsepower needed for your pump. A simple rule to follow is you should be able to clear all of the gallons of your pool in an 8 hour period of time. You can use the following as a guideline.

Pool Size Gallons Gallons/hr Gallons/minute Suggested HP
15 ft 5,300 660 11 1/2
18 ft 7,650 960 16 1/2
21 ft 10,400 1,300 22 3/4
24 ft 13,600 1,700 28 1.0
27 ft 17,20 2,150 36 1.5
Determine Above Ground Pool Filter Size