Includes powerheadFeatures a unique baffle system that prevents the substrate and organisms from being disturbed yet also allows enough water to flow through the eliminate any stagnant areasWater Capacity: 2.5 gallonsDimensions: 13.5" L X 4.5" W X 12" TDoes not include the light. The Aquafuge Small Light, 18 Watt is recommended.The AquaFuge provides ideal growth conditions for food items, such as copepods and ampipods, to feed invertebrates and fish in the main tank.It provides a controlled growing area for macroalgae, which can be used to reduce "nuisance" algae in the main tank and provided a "nursery" area for a variety of organisms.