The most popular filters today. Easy to maintain and install.
Top Mount Sand Filter : HWDS220T, HWDS244T, HWDS270T, HWDS310T2
AND HWDS360T2 Sand Filter Models.
HAYWARD "PRO-SERIES"
HIGH RATE FILTER WITH VALVE
High-rate 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. They operate on the basis of "depth" filtration; dirt is driven
through the sand bed and trapped in the minute spaces between the particles
of sand. Initially, a clean sand bed will remove larger particles, and
then, as the bed starts to load up with dirt, it will remove finer particles.
Cleaning of the media, or sand, is accomplished through reversing the
flow through the filter, to the "waste" line. This is known as backwashing.
The oldest and most popular method
of filtration is sand. Sand filters share two things in common: 1) When
in the filtration mode, water always flows from top to bottom; 2) They
all have some sort of lateral or under drain with slots to hold back
sand while allowing clean, filtered water to pass through.
