Protein skimmers create foam by mixing saltwater and air together. Protein skimming works through adsorption, which is the firm attachment of an extremely thin layer of molecules to the surface of air bubbles. Protein and other organic compounds in the water form a coating around the bubbles as they rise to the top of the foam riser tube of your skimmer. The foam cascades over the top of this tube, filling the collection cup. The captured foam is emptied from the collection cup before it can re-enter the aquarium. Proteins and other organics are removed before they can turn into nitrogen compounds or other toxins that may be harmful to your aquarium inhabitants. Protein skimming helps you maintain a healthy environment for your fish and invertebrates. Filtration equipment of this type is the most important investment you can make. It is the life support system of your saltwater aquarium. Helps to prevent tank wipe out (toxic tank syndrome), which is the accumulation of unknown toxins in the water. Helps to prevent the buildup of toxins that can kill all susceptible fish and invertebrates within just a few hours (this usually occurs overnight).Protein foam skimming completely removes most organics from the system before they can break down, including water-soluble protein, amino acids, some dyes, fatty acids, fats, carbohydrates, enzymes, detergent, phosphorus, iodine, detritus, metals such as zinc and copper, some algae, protozoa, bacteria, and other organics. Protein skimming helps to aerate the system and increase the oxygen level in the aquarium. Easily adjusted and low maintenance. Comes pre-assembled and includes two-way plastic valves and plastic assembly. For internal use only. There are no complicated plumbing requirements.