Types of pool filters :

The three main types of pool filters are sand, cartridge, and diatomaceous earth.

• Sand filters : involve a tank full of sand that traps contaminants as water percolates through. While sand appears smooth to the naked eye, when viewed under a microscope each grain has prickly, rough edges that grab contaminants. Dirt and debris remain trapped in the sand, and clean water travels to the bottom of the tank and returns to the pool.
• Cartridge filters : consist of pleated cartridges that capture debris when pool water flows through a tank. The pleats trap contaminants as small as 10 microns, and clean, filtered water returns to the pool. Most cartridge filters trap debris in the 10-15 microns range; a higher filter efficiency than sand filters. However, they are more expensive than sand filters and involve a different, yet simple maintenance process.
• Diatomaceous Earth (DE) filters : contain grids covered in a crumbly white powder that captures unwanted contaminants but allows water to flow through. The powder is made from crushed fossils of single-celled algae called diatoms. Diatoms contain high amounts of silica, which lends DE the bulk of its filtration power. Silica is also a major component of sand.