How Big Should My Pool Filter Be?

Overview

A pool filter that is too large for the pool will waste energy by over-cleaning the pool water. A pool filter that is too small will have to work harder to clean the water and may not even be able to keep the water clear.

Sizing

The choice of a pool filter depends on the maximum flow rate of the pump and the type of medium chosen for filtration. The size of the filter will be stated in square footage of the filtration medium. Sand filters handle a maximum flow rate of 15 gallons per minute per square foot of medium. Demetrius earth, or DE, filters handle a maximum flow rate of two gallons per minute per square foot. Cartridge filters handle a maximum flow rate of .25 gallons per minute per square foot. Pool pumps vary from ¾ horsepower (HP) to 3 HP. Each size has a different flow rate. Determine the square footage of filtration medium required by the flow rate of the pump used to pump water through the filter. A filter that is too small to handle the flow will fill with debris too quickly and put stress on the pump. A filter that is too large is better, but the larger size is more costly when a smaller filter is sufficient for the flow rate of the pump.

Sand Filter

The following are optimal square footage of filtration medium for common pump sizes for a sand filter: A ¾ HP pump requires 2.7 square feet of filtration medium. A 1 HP pump requires 3.4 square feet of filtration medium. A 1.5 HP pump requires 4.3 square feet of filtration medium. A 2 HP pump requires 5.8 square feet of filtration medium. A 2.5 HP pump requires 7 square feet of filtration medium. A 3 HP pump requires 8 square feet of filtration medium.

DE Filter

The following are optimal square footage of filtration medium for common pump sizes for a DE filter: A ¾ HP pump requires 24 square feet of filtration medium. A 1 HP pump requires 36 square feet of filtration medium. A 1.5 HP pump requires 48 square feet of filtration medium. A 2 HP pump requires 60 square feet of filtration medium. A 2.5 HP pump requires 72 square feet of filtration medium. A 3 HP pump requires 84 square feet of filtration medium.

Cartridge Filter

The following are optimal square footage of filtration medium for common pump sizes for a cartridge filter: A ¾ HP pump requires 100 square feet of filtration medium. A 1 HP pump requires 150-200 square feet of filtration medium. A 1.5 HP pump requires 300 square feet of filtration medium. A 2 HP pump requires 400 square feet of filtration medium. A 2.5 HP pump requires 500square feet of filtration medium. A 3 HP pump requires 600 square feet of filtration medium.

Keywords: size pool filter, size DE filter, size sand filter, size cartidge filter

About this Author

Emily Patterson has been creating content for websites since 1996. She specializes in home improvement, natural body care and natural cleaning articles. Patterson holds a computing certificate from Penn State University.

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