The SM series of protein skimmers are ideal for tanks that do not have a lot of space in the sump available. The SM207 has a tiny footprint with a space saving pump design that keeps everything very compact. The new output valve design allows for more control over the water level inside of the protein skimmer compared to previous models. The Skimz SM207 the perfect protein skimmer aquariums from 100 up to 300 gallons