Proper Pump and Filter Sizing Saves Energy - and Money!
Proper pump sizing makes sure the water in the pool or spa can pass through filtration, disinfection and heat equipment often enough to clean up the dirtiest mess - but economically enough to save energy and money!
- Determine Proper Turn-over rate
- Determine the pump that can deliver that much water
- Determine the filter that can handle that much water
Steps to determine Turn-over Rate
Turn-over Rate: The maximum time it takes to pass all the water through the system can vary by national, state and local codes, but generally guidelines suggest the following:
- Residential Pools: 6 - 8 hrs max
- Commercial Pools: 4 - 6 hrs max
Good designers make sure to have enough pump and filter to have a turn-over rate comfortably faster than the maximum times above.
To determine turn-over rate:
- Divide Pool Volume
- by Turn-over Rate in hours (from above)
Pool Volume (gallons)/turn-over max(hrs)/60 (mins/gallon) = turnover rate in GPM, (gallons-per-minute)
Common Filter Media Rate
High-Rate Sand: 5 - 20 gpm/ft2
Cartridge: 0.375 gpm/ft2
Diatomaceous Earth (DE): 2 gpm/ft2
It is always recommended to oversize the pool filter. Adequate filtration is the primary source of clean clear pool water. An undersized filter can lead to numerous problems, including cloudy pool water, increased chemical demands, pH swings, and unsafe swimming pool water.
Maximum pump gpm must be used when calculating the minimum required filter area. Exceeding the filter media rate will result in many negative effects to the equipment and poor pool water quality.