A system for controlling administration of medical fluid includes a fluid passageway to which is attached a first flow regulator, a second flow regulator, and a flow detector. The system also includes a controller for controlling the first and second flow regulators in response to a measurement taken by the flow detector of fluid movement in the fluid passageway. The first flow regulator, such as a pump, is configured to maintain fluid movement at flow values greater than an unrestricted flow value. The second flow regulator, such as a variable adjustable valve, is configured to maintain fluid movement at a flow value less than the unrestricted flow value. A method of controlling administration of medical fluid includes obtaining a target flow value, moving fluid through the disposable assembly, taking a measurement of fluid movement in the disposable assembly, and actuating a flow regulating apparatus.