Straightforward and safe water level controller for fresh and sea water with optical control sensor and independent thermal safety sensor. A constant water level keeps the salt concentration constant in seawater aquariums. Incl. Turbelle® High Jet 5030 dosing pump with integrated dry running and blockage protection, magnet holder, 12V DC power supply unit, tube and tube holder. Suitable for placement in cabinet filter systems or on the edge of the aquarium. The sensor holds on glass panes up to 15 mm (0.59”) and the tube holder up to 22 mm (0.87”).