Protein skimming is a very important part of the filtering process of a marine tank. The build up of proteins in aquarium water is unhealthy for the inhabitants of the aquarium because it reduces the overall water quality, oxygen levels become reduced,nutrient levels can become too high and water can become discolored with a yellow cast. Protein is like oil and it impossible to remove thru normal filtration, it must be separated from the water. water changes will remove some, but not all of the protein. Skimmers work by spinning the water in a vortex which separates the protein from the water and creates a foam that forced  up into a collection cup for removal. All of the water moves thru the skimmer  so all of the water is being cleaned all of the time. Ocean water is churned by the waves and the protein is forced to the surface, this is the foam that can be seen on the top of the  water, as the water rolls onto the beach, the sand traps and removes the protein and the clean water rolls back out to sea. This does not happen in an aquarium so it must be mechanically removed.Skimming also helps to reduce nitrates and phosphates and unwanted algae growth.   There is a large selection of protein skimmer available today and the one you choose will be determined by the size of your tank and the type of filters you have. Some skimmers are designed to go in sump and others hang on the back of the tank. All are rated for the size of the aquarium they are designed for. These are a few of the skimmers that we keep in stock.