A renal therapy apparatus including at least two feedback controls is disclosed. Each control includes an estimated volume calculator to calculate an estimated volume based on a set flow, a comparator to compare the estimated volume with a measured volume, a volume deviation determining means to determine a volume deviation based on the comparison, a correction calculator to calculate a correction based on the volume deviation, a flow control generator to generate a flow control signal based on the calculated correction amount and the set flow, and a feedback control output to output the controlled flow control signal to a pump associated with each feedback control. A flow correction distributor includes an input to receive correction signals from the correction calculator, a limited correction signal calculator to calculate a limited correction signal for the input correction required signals, and an output to output each calculated limited correction signal to the feedback control from which its underlying correction required signal has been received.
