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. NOTE: The powerhead could either be a ViaAqua 480 or 820. One is not superior to the other.