A protein skimmer is a device used in aquariums, particularly saltwater tanks, to remove organic waste. It works by creating bubbles that attract and trap proteins and other impurities from the water. As the bubbles rise, they carry the waste to a collection cup, where it can be easily removed. These skimmers help maintain water quality by reducing harmful substances, which can lead to algae growth and affect fish health. Regular use of a protein skimmer can enhance the overall environment in an aquarium, making it cleaner and safer for aquatic life.