The Comline DOC 9001 DC is designed for use in mixed reef aquariums with 20 to 160 liters (5 to 42 US gallons), soft coral aquariums up to 140 liters (37 US Gallons) for sensitive reef biotopes with SPS corals up to 60 lites (16 US Gallons). The unit works according to teh Tunze Flash Skimming principle, it is able to take in the water in the middle of the aquarium in a plankton friendly manner or through a surface extraction Surface Kit and can therefore be used as a stand alone solution in small aquariums.