ABSTRACTThe design, installation, and operation of a compressed air system to eliminate thermal stratification in lakes is described. During a year‐long field test on a 19 ha lake, this system effectively eliminated thermal stratification, increased dissolved oxygen, and kept part of the lake ice‐free during winter. This system has the capability for use in larger reservoirs and, used for control or elimination of stratification in lakes, is a promising tool for alleviating problems caused by thermal stratificat