Embodiments of the invention provide a constant flow variable speed pump for use in a recirculating aquaculture application. The pump includes a housing with an inlet and an outlet, an impeller positioned within the housing, and a motor coupled to the impeller and configured to rotate the impeller within the housing, causing water flow through the recirculating aquaculture application. The pump also includes a controller in communication with the motor and configured to drive the motor. The controller is configured to adjust a speed of the motor to maintain a first flow rate through the recirculating aquaculture application between a first start time and a first stop time according to a first user-defined schedule, and to maintain a second flow rate through the recirculating aquaculture application between a second start time and a second stop time according to a second user-defined schedule.