Abstract: A fountain aerator for propelling and aerating water includes a float having a flow tube extending therethrough for suspending the aerator in a body of water. A motor base assembly contains a motor provided with a rotatable output shaft. An open ended housing is spaced from the float and connected between the flow tube and the motor base assembly. A wear ring is secured within the housing and defines a central opening therein. A covered impeller is retained in the housing in spaced relationship with the float and is coupled to the motor output shaft for rotation therewith. The impeller has a series of radially extending blades which define a series of outlet passages in communication with the inlet. A flow straightener is spaced from the float and fixed to the housing in overlying, surrounding relationship with the impeller.