Fisher Pumps Inc., of Greeley, Colorado started in 1980.  Fisher Pumps offers unique aeration equipment for the municipal and industrial water and wastewater markets.  The unique design of Fisher pumps was originally created for pumping extremely abrasive fluids, such as drilling fluids used in the oil fields.  All other competitive submersible pumps use a mechanical bearing or bushing to stabilize the drive shaft and impeller. When pumping abrasive fluids, these bearings or bushings wear out very quickly.  Fisher Pumps has eliminated this problem by designing a double discharge impeller case. This double discharge eliminates any side thrust on the drive shaft and impeller allowing Fisher Pumps to operate without mechanical bearings or bearings submersed in the fluid. While being successful in pumping highly abrasive and viscous fluids in the oil fields, we started experimenting with different impeller curves. From extensive testing, we developed three impeller designs: The mud style for high percentage solids in fluids with high viscosity. The irrigation style for efficient pumping capacities per Horse Power for up to 80 feet of TDH.  The manure style for pumping fluids with straw and high percentage solids that will not plug while pumping.