There is provided a method of preparing a mixed liquid having a first property and a second property. The method includes providing a first set of liquids, a second set of liquids, and a third set of liquids. The method includes combining the provided sets of liquids. Further, the method includes varying at least one of the liquid flows of the first and second sets and at least one liquid flow of the third set to adjust the first property and the second property to their respective predetermined values in the resulting mixed liquid flow.