A method of dosing detergent into a cleaning chamber of a washing machine using gravity. The method comprises providing an amount of detergent to be used in a washing machine, providing a detergent storage tank, providing a diverter valve comprising a detergent inlet, a detergent outlet, and an air vent, presenting a user interface at a location accessible to a user for a user to input load characteristics, relaying information via electrical signals from the user interface to a controller in electrical communication with the user interface, determining a dosage requirement and dispensing a fluid into the cleaning chamber.