Three case studies were presented in this publication. The applications differ in their major focus.

Case 1: Lake Steinbrunn is a small lake with halocline and thermocline stratification. The tasks of the deep water aeration were the reduction of the salinity by mineralization and the establishment of a completely aerobic Hypolimnion in the second step. All limnological data came from the limnology Office DWS Donabaum in Vienna.

Case 2:  Lake Rundstedt is a 230 ha open cast mine has been filled with a layer of approx. 20 m of industrial disposals. This open cast mine has been refilled with water. After refilling 3 deep water aerators were taken in operation to provide enough oxygen to avoid Ammonia releases to the Hypolimnion. All used data came from the Geo-consulting office IHU and the limnologic Office CUI Magdeburg.

Case 3: The K-Teich in Wiener Neudorf. This small lake has been monitored really serious during the last 20 Years from the limnology Office DWS Donabaum in Vienna. The Measurement indicates strongly the oligotrophication process and the dependence of the Water quality and the operation characteristic of the aerator.