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Cleaning Capacity
The skinny on how filter media stacks up.
While the "big three" - sand, diatomaceous earth (DE),
and cartridge - continue to dominate the filter media world,
the question still remains, "Which is best?" That of
course depends on how fine a particle do you want to filter?
Where will it be used and what is your budget? How much time
do you want to spend on maintenance? Also the subjective nature
of filter media in its applicational use makes direct comparison
difficult. Here, however, are a few known points from which to
compare and contrast the media types.
SAND
Size of particles filtered: 20-40 microns
Estimated filter rate: 15-20 gallons per minute per square foot.
Relative cost of filter: $$
Relative cost of media: $
Cleaning frequency: Whenever the pressure reaches 10 psi or higher
than starting pressure. Usually depends on bather load, hydraulics
and filter design.
Replacement frequency: Typically after 3-5 years the sand grains
have worn smooth and need to be replaced. This is indicated when
the pressure fails to fall below 5 psi of initial pressure.
Strongest selling point: Requires little attention.
(DE)
Size of particles filtered: 2-5 microns
Estimated filter rate: 1-3 gallons per minute per square foot.
Relative cost of filter: $$$
Relative cost of media: $$$
Cleaning frequency: Whenever the pressure reaches 10 psi or higher
than starting pressure. Usually depends on bather load, hydraulics
and filter design.
Replacement frequency: After each backwash.
Strongest selling point: Provides the finest filtration of the
three media.
CARTRIDGE
Size of particles filtered: 10-25 microns
Estimated filter rate: 0.375-1 gallons per minute per square
foot.
Relative cost of filter: $
Relative cost of media: $$
Cleaning frequency: Whenever the pressure reaches 10 psi or higher
than starting pressure. Usually depends on bather load, hydraulics
and filter design.
Replacement frequency: Typically 3-7 years.
Strongest selling point: No backwashing provides easy maintenance.
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