In most reef systems, it is the focus of the entire filtration system. A skimmer will remove non water-soluble compounds such as proteins, lipids, carbohydrates and other organic materials which lead to algal growth. A skimmer removes dissolved organics by a method known also as foam fractionation.
Water is rushed through the skimmer at a high velocity.
Air is then introduced in a fine stream of bubbles. The removal of organic material benefits the tank in many ways. Most importantly, it removes the material that would otherwise become fuel for excessive algae growth. Secondly, it cleanses the water which raises the redox potential. It also acts as a mechanical filter, removing particulate matter and detritus.