A method and apparatus for obtaining a solution from a solid product in contact with a liquid is provided. A solid product is housed within a dispenser. A liquid is introduced into contact with the solid product. The solution formed between the solid product and the liquid is collected, and a makeup liquid can be added thereto to further dilute or control the concentration of the formed solution. The amount of makeup liquid added to the solution can be controlled based on the temperature of the liquid to provide an automatic, continuously variable amount of liquid added to the solution. In addition, a method of providing a pressure independent control of the makeup liquid is also provided.