Of the many possible methods for reducing levels of organic matter in aquarium water, one of the simpler and more convenient is foam fractionation, or protein skimming.
Protein skimming is a filtration method used to remove 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, injection of air bubbles into the aquarium water creates a meringue like foam when organic molecules collect at the air-water interfaces of the bubbles. This foam is captured in the collection cup and disposed of.
Foam fractionation is an important part of the successful maintenance of a marine aquarium. It is the only method available that physically removes organic pollutants from the water. All other techniques simply sequester pollution within filter media, which are then removed and replenished with fresh media. Meanwhile, pollutant molecules may be constantly exchanged between the media and the aquarium water, reducing the overall effectiveness of the filtration system.
For marine aquariums, foam fractionation is a practical and simple way to control this organic pollution.