sera marin Protein Skimmer PS 600 S A protein skimmer is indispensable in a saltwater aquarium. It regulates the removal of proteins, phosphates and other substances, prevents algae growth and increases the oxygen level. In addition to the existing marin range, sera has developed two powerful protein skimmers that produce tiny bubbles and therefore ensure excellent skimming performance. Larger aquariums with a separate filter tank allow to operate the sera marin Protein Skimmer 600 S directly inside the filter sump. It is easy to adjust and ensures highly effective protein skimming in saltwater aquariums.