Of the many possible methods for reducing levels of organic matter in marine aquarium water, one of the more simple and most convenient is foam fractionation, or protein skimming with an aquarium protein skimmer. Protein skimming is a filtration method used to remove (DOC) dissolved organic compounds before they break down into toxic ammonia and nitrite compounds. In a process analogous to the production of sea foam in surf, the injection of air bubbles into the aquarium water creates a froth like foam when organic molecules collect with the air-water ions of the bubbles. This foam is captured in the collection cup and disposed of. See our large selection of protein skimmers at great prices!