Hydor Seltz Aquarium Water PumpThe Hydor Seltz Aquarium Water Pump is an all purpose high performance universal pump that is suitable for fresh water and marine aquariums. This water pump has a flow control system using a flow control knob for adjustable water flow which allows many different uses and applications. One-piece rotor assembly and filter sponge. Suitable for biological, wet-and-dry filters and for water circulation. Equipped with tube connectors for non submerged use (tube connectors included). Works in and out of water--also for non-submersible use.