Identification

• A swimming pool filter consists of a pump to circulate the water through a filtration medium. The debris particles get caught in the filter and the cleaned water is pumped back into the pool.
  
  

Sand

• The most common type of swimming pool filters use sand to filter debris out of the water. These are the least effective filters for cleaning the water. They also need more maintenance than the other types, requiring periodic backwashes.
  
  

Cartridge

• Cartridge-based swimming pool filters use a paper cartridge to remove debris from the water as it is pumped through. Cartridge filters can last for several years if properly cleaned and maintained. The paper cartridges can be cleaned by removing them from the filter and washing them down with a garden hose and high-pressure nozzle.
  
  

Diatomaceous Earth

• Some swimming pool filters use the natural filtration properties of diatomaceous earth to sanitize the water. The powdered diatomaceous earth is mixed with water and poured directly into the skimmer, where the pump system evenly distributes it throughout the pool water.
  
  

Considerations

• The size of your pool and amount of dirt that falls into it will affect the type of filter you should buy. Cartridge and diatomaceous earth filters do not handle large debris well, so a sand filter may be best if you have trees dropping their leaves into your pool.