Abstract: An improved reverse osmosis water purification system having improved adjustable clamp means for securing the filter and membrane containers to each other and to the reservoir, together with a discharge hose adapted to minimize splashing and noise, a modified clothespin mounted adjacent the discharge end of the waste water recycling hose to facilitate securing the discharge end of the hose, and means for automatically matching the supply of input water to the water level in the reservoir without requiring manual regulation by the user or complex and expensive electronic control systems and a reservoir with filtered air.