The first thing to determine is the desired turnover time or in layman terms how long it takes for the pool pump to cycle all of the swimming pool s water completely.
Pool pump sizing.
You might think bigger is better in terms of pump size but a pump that is too big can cause serious problems.
The first step in sizing your pool is to know the volume of water in your pool which is the average depth.
We can see that for our example pool we can determine the following.
Below we ll run through how to easily figure it out step by step and choose your pool pump confidently.
We will use that gpm to calculate our pool s feet of head.
Oversizing pumps have become such an issue that the state of california a big pool state recently enacted a law to control how big of a pump could be placed in a swimming pool.
Calculate the volume of your pool.
Now most pool owners don t have a vacuum gauge installed before the pump.
Divide the pool into the above shapes then add together.
Determine maximum flow rate.
Measure the shallow end depth.
If you want to turn over your 20 000 gallons once in 5 hours you will need to average at least 67 gallons per minute gpm.
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 encounters resistance at the filter.
How to determine gallonage.
Use this formula to determine your turnover rate.
You have now completed your pool pump sizing and will be able to purchase a pool pump that will work efficiently and safely with your pool system.
Length x width x average depth x 6 9 pool capacity in gallons round.
How to figure out what pool pump size you need.
Water pumps of 1 1 5 and 2 horsepower are very common and for the average size pool very oversized.
This will eventually burn out the pump motor and your filtration will also be compromised.
The size of your pool filter is directly related to the pool pump you have selected.
If you can get of a vacuum gauge not a pressure gauge unscrew the front pump drain plug and thread the vacuum gauge in its place.
Pool volume in gallons turnover rate in minutes flow rate.
Determine your flow rate range.
Calculate minimum flow rate.
Length x width x average depth x 7 5 pool capacity in gallons oval.
Length x width x average depth x 5 9 pool capacity in gallons free form.
Multiply the pump vacuum by 1 13 to measure resistance before the pump add the two together to compute the total resistance in the system.
22 5 60 gpm or flow rate range.
Measure the deep end depth.
A pump s flow rate is dependent on the feet of head of your plumbing system and that measurement is featured in every pump curve chart.
There are a few primary factors that go into finding the right size pool pump.
An ideal turnover time is 8 10 hours.
