Water filter

A water filter removes impurities by lowering contamination of water using a fine physical barrier, a chemical process, or a biological process. Filters cleanse water to different extents for purposes such as providing agricultural irrigation, accessible drinking water, public and private aquariums, and the safe use of ponds and swimming pools.

Filters use sieving, adsorption, ion exchanges and other processes to remove unwanted substances from water. Unlike a sieve or screen, a filter can potentially remove particles much smaller than the holes through which its water passes.Types of water filters include media filters, screen filters, disk filters, slow sand filter beds, rapid sand filters, cloth filters, and biological filters such as algae scrubbers.