A method of using a system to apply liquid over a selected area includes providing a source of liquid, a first tube for transporting liquid from the source through the system, a connector, a check valve and a spray device. The connector includes a projection extending into the first tube. The projection has an inlet in fluid communication with the first tube. The connector further includes an outlet and a passageway in fluid communication with the inlet of the projection and the outlet of the connector. The check valve has an inlet in fluid communication with the outlet of the connector and an outlet. The check valve is operable to permit the passage of liquid from the inlet to the outlet upon pressurization of the liquid above a threshold pressurization level. The method includes the steps of introducing an amount of liquid to be applied to the selected area from the source of liquid to the first tube at a pressure below the threshold pressurization level of the check valve and providing pressurized air through the first tube to pressurize the liquid in the first tube above the threshold pressurization level of the check valve, thereby transporting liquid from the first tube, through the connector and the check valve and through the spray device in response to pressurization of the liquid. The liquid may be ozonated water.
