Abstract: An apparatus and method for measuring and mixing liquids is described. First and second vessels are connected to an aspirator so that reduced pressure is produced in the second vessel as a first liquid flows to the first vessel. Reduced pressure motivates flow of a second liquid into the second vessel until a predetermined level is reached. A conduit opens between the first and second vessels. The aspirator draws liquid from the second vessel to the first vessel while the conduit allows liquid from the first vessel to flow to the second vessel. Thus, the liquids are mixed until a predetermined level of liquid in the first vessel is reached.