Take control of the aquarium cleaning process with the Fluval GravelVac multi-substrate cleaner. Available in 2 sizes. Suitable for all substrate types, this GravelVac makes cleaning a breeze thanks to its total control thumb regulator. This simple and effective mechanism allows the user to smoothly adjust the water flow as waste and debris is removed from the tank. No constant starting and stopping means no time wasted! Designed for both saltwater and freshwater, the cleaner also comes with an extendable nozzle for accessing those hard to reach areas. It also includes an easy start siphon that primes the unit with just a couple quick pumps!