In this article research results of a mixing and gased system for sewage plants will be presented. The results were obtained by measurements in pure water and sewage in tanks with original size. The used system is valuated with regard to power and oxygen input from a process engineering point of view. By applying a model for fluid-streamdistribution in chanels a new gasing ring that leads to considerable efficiency gains was developed. Furthermore the characteristics of the stirrer are demonstrated. An experiment for the correlation of substance transfer and efficiency gains in dependence on the size of the stirrer and vessel as well as on the geometry of the vessel is presented by using comparative measurements in tanks with a similar geometry and in sewage. Based on all research results dimension instructions for stirrer size in dependence on the tank geometry can be set.