There is a lot of confusion about various filters, and many different opinions. Here are a few facts to consider. The first is that a pool can be properly maintained with any of the filter systems available: Sand, Cartridge, or Diatomaceous Earth (DE). Here is a brief description of each type:

Sand – The bullet proof filter: The principle behind this filter is that water is pushed through the filter sand, somewhat like an espresso machine. Dirty water goes in the top and clean water exits out the bottom.

Cartridge – The economic low maintenance filter.
This one is easy to understand. Water passes though a filter material and the filter captures the debris. This is just like the water filters used under your sink. Cartridges have much more available area to filter than sand.

DE – The water polisher.
Diatomaceous earth is mined and is the fossilized exoskeletons of tiny diatoms. They are used to coat “grids” in the filter housing and act as tiny sieves to remove debris.