D.E. Filters are the most common filter type in my area so I will touch on these filters first. D.E. Filters or Diatomaceous Earth Filters offer the best filtration of the three types. They use a set of grids or cartridges depending on the filter type and a coating of D.E. Powder (Diatomaceous Earth). The D.E. coats the grids and acts as a barrier trapping dirt, debris, algae, and organic particles. This allows a D.E. Filter to filter down to an amazingly low 3 microns.

 

A little about what a micron is for you:

 

A "micron" is an abbreviated term for "micrometer", or a millionth of a meter (1/1,000,000 meters). This is about .00004 inches. For Size comparison, a human red blood cell is about 5 microns across. A human hair is about 75 microns across (depending on the person).

 

So a micron is a very small measurement and a D.E. Filter will give you the best water quality of the three filter types.

 

Another benefit of a D.E. Filter is that the design allows for a very small amount of filter sq ft area to keep your pool crystal clear. Typical D.E. Filter sizes are 36 sq ft, 48 sq ft, 60 sq ft, and 72 sq ft (they also make a 100 sq ft Quad D.E. Filter). So you can easily get away with using a 48 sq ft D.E. Filter on a 20,000-gallon pool. So don't let the smaller sq ft size fool you into thinking that a D.E. Filter is inferior to say a 200 sq ft Cartridge filter or a 300 lb Sand Filter. The D.E. Filter just utilizes the sq ft of filtration area much more effectively with the coating of D.E. on the grids (or cartridges in the case of a Quad D.E. Filter).

 

Another benefit is the ability to backwash a D.E. Filter in between cleaning it. This is a process in which the water flow is reversed forcing water inside the grids and pushing dirt and algae off of the grids and out the backwash pipe. Convenient if the pool gets a lot of dirt and use each season.

 

The drawback of D.E. Filter is that they can be messy to take apart and clean, especially if your backyard is all cement. The old D.E. powder can linger for months. They can also be challenging to take apart and clean. Many cities require it to be plumbed to a P-Trap or ban them entirely.  

 

The Good:

- Filters down to 5 Microns or less - excellent

- Can be backwashed in between cleanings

- Only have to take it apart and clean it every   six months (In most cases)

- Grids are long lasting and durable

- Water clarity is very good

 

The Bad:

- Can be a pain to take apart and clean

- D.E. is messy and gets everywhere

- Grids can tear and leak D.E. into the pool      

- Filtration Sq Ft. is limited 

- D.E. is banned in some areas and huge fines     can occur if it is in the street