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[[Image:Icon_biosand.png|right]]

[[Image:rapid sand filter.jpg|thumb|right|300px|Rapid sand / gravity filtration box. <br>Photo: [http://water.me.vccs.edu/concepts/filters.html Types of Filters.]]]

The rapid sand filter differs from the slow sand filter in a variety of ways, the most important of which are the much greater filtration rate and the ability to clean automatically using backwashing. The mechanism of particle removal also differs in the two types of filters - rapid sand filters do not use biological filtration and depend primarily on adsorption and some straining.