What kind of
Filter should I use with my system?
There are three main types of filter systems out there Sand, Cartridge,
and D.E. filters. You should first determine your pump size. This
will then determine the filter size needed for your system.
Sand
– Filter Range 20 to 40 microns. The oldest and most popular
method of filtrations is sand. Sand filters use a special filter
sand, normally .45 to .55 mm (also known as pool-grade #20 silica
sand), because it has sharp edges that serve to separate particles,
allowing filtration to take place. Sand filters are the least expensive
of the three types of filters but only filters particles down to
20 to 40 microns in size.
Cartridge
– Filter Range 10 to 20 microns. Cartridge filtration has
been available for a relatively long time, and recently has begun
to enjoy rapid growth and acceptance. When water passes through
a cartridge filter, dirt is screened out at the surface of the cartridge
element. When clean, the element will trap larger particles, with
finer particles being filtered out as the pores of the element become
clogged by the larger debris. The cartridge element can be removed
and cleaned by pressure washing inside and out with a garden hose.
D.E. (Diatomaceous
Earth) – Filtration Range 1 to 3 microns. Many pool
professionals consider D.E. filtration to be the finest, because
it is capable of removing smaller particles than either sand or
cartridge. Diatomaceous earth is a porous powder with microscopic
openings, that, when magnified, look like tiny sponges. Clear water
can pass through these openings but particles, as small as one to
three microns are trapped the first pass through the media. All
D.E. filters have internal elements that become coated with D.E.
It is this “filter cake” that strains dirt, dust, algae
and some forms of bacteria from the water. Similar to sand filters,
when a D.E. filter becomes dirty, it is cleaned either by backwashing
the clogged D.E. to the “waste” line or regenerating
and draining. To restore filtration, a fresh “charge”
of D.E. is added to the filter.