Abstract: An automatic liquid dispenser dispenses precisely measured amounts of cleaner/deodorizer into a toilets tank through a closed system is further disclosed. The invention consists of a housing that connects between the water supply line and the water supply inlet of a toilets tank and a refillable liquid storage container. The housing is installed in the flow path of the water supply used to fill a toilets tank for flushing. During the filling of the toilets tank the flow of water is directed over an orifice causing a siphon to be created. This siphon compresses a spring loaded ball check allowing liquid cleaner/deodorizer to flow into the water supply filling the toilets tank When the tank is full it contains a predetermined and precisely mixed amount of water and cleaner/deodorizer.