High Quality Content by WIKIPEDIA articles! A protein skimmer or foam fractionator is a device used mostly in saltwater aquaria to remove organic compounds from the water before they break down into nitrogenous waste. Protein skimming is the only form of aquarium filtration that physically removes organic compounds before they begin to decompose, lightening the load on the biological filter and improving the water`s redox potential. Although the process of foam fractionation is commonly known for removal of waste from aquaria, it is, in fact, a rapidly developing chemical process used in the large-scale removal of contaminants from wastewater streams and the enrichment of solutions of biomolecules.