Water level controller with simply one sensor for nano fish tanks or little aquariums with up to 200 liters (55 USgal.), placeable into closet filter systems or on the advantage of the fish tank. Scope of shipment: prepared for installment with 11V power supply, low-voltage metering pump, 3m (118 inch) hose pipe, magnet holder for as much as 10mm (0.39 inch) glass density and a safety pay for the sensing unit.