Intended for submerged turbine aeration in water and waste water treatment plants, the three blade version of the GDX turbine aerator combined with a sparge ring supplied by a blower disperses gas and feeds oxygen to the biology. The superior design of the anti-ragging GDX impeller optimizes the process requirements with the impeller performance. Gassing rates decrease in these types of biological processes and by removing three of the blades, the impeller cost is optimized with the process requirement. In addition, the blade profile sweeps back to prevent the impeller from collecting fibrous rags found in waste water treatment plants which cause the mixing system to fail. The submerged turbine aeration system functions as a hybrid between a diffusor/compressor only aeration system and a mixer only low speed surface aerator system especially suited for swing zones which need to operate with both the air on and off.