Sand Filters
Sand filters require little maintenance, are highly economical and adequately filter your pool water, though not as well as a Cartridge or DE filter!
Sand pool filters will trap particles of debris as small as 12 "microns" in size, which is adequate for any outdoor swimming pool. The sand inside the filter tank should be
changed out with fresh sand every 2-3 years.
The only regular maintenance required for a sand pool filter is a quick cleaning once every week or two. This quick and easy cleaning process is called "backwashing",
and basically means reversing the flow that has collected in the sand is carried out of the filter.
Cartridge or "Element" Filters
Cartridge filters consist of a large tank with a paper or polyester "element" that fills the entire inside tank volume from the bottom to the top.
The filter element may last only one year, or may last many years depending on use and how carefully it is cleaned. Cartridge pool filters will trap particles of debris
as small as 8-10 microns in size.
Cartridge pool filters require periodic cleaning to remove the loose debris from the filter element, and once or twice each swimming season the filter element will need to
be soaked in a filter cleaning solution to remove more stubborn stuck-on debris and oils. Depending on how a cartridge filter is sized and how dirty the swimming pool is, the element may need to be cleaned once a month, once a week or more frequently.
DE Filters
The "DE" stands for Diatomaceous Earth … fancy words for a natural or synthetic powder that coats the inside of the filter tank.
A DE pool filter traps debris down to 2-3 microns in size, resulting in better water clarity than pool sand filters and cartridge pool filters can provide. The filter element
inside the DE filter does not actually trap the debris by itself. The coating of DE powder on the outside of the element is actually used to collect the fine debris as the dirty
pool water is passing through.
When a DE filter is full of dirt from the pool water and the pressure gauge indicates that it needs to be cleaned, you do not have to immediately backwash the
filter, like you would with a sand filter. You can first regenerate or “bump” a DE filter to clean it. This regenerating process shakes or scrapes all of the DE
powder and debris off of the filter element inside the pool filter tank. All of the debris and DE powder settles to the bottom of the filter tank, and when the filter is
turned back on the DE powder recoats the filter element to continue to filter the pool water. This can be done several times before all of the debris and DE
powder must be backwashed out of the tank. The backwashing process for a DE pool filter is similar to the backwashing of a sand pool filter. The flow of water
through the filter is reversed, and all the dirt flows out of the filter through a waste port.
A disadvantage of the DE filter is that each time you backwash the dirt out of the pool filter tank, the DE powder also flows out. Before you can continue to filter,
you need to add fresh DE powder.