The coralife 30G marine Filter with Protein Skimmer is an all-in-one filter and protein skimmer. Ideal for consumers stepping into the saltwater hobby for the first time. The easy to use protein skimmer has a needle wheel impeller & adjustable Air flow dial. Unlike most protein skimmers, this skimmer will not be affected by water level fluctuations. For saltwater applications only (protein skimming only works with saltwater). the filter portion has a cartridge with activated carbon and a phosphate filter pad. The heater clip accommodates the aqueon 100 watt preset aquarium heater.