Abstract: Disclosed herein is an apparatus that efficiently clears solutes from blood of patients with renal disease solely by convection and with a single filter that includes a hemofilter, a blood pump for drawing blood from a patient and propelling the blood into a mixing chamber, a mixing and detention chamber where the blood and a non-isosmotic diluent are mixed and are allowed to approach or reach equilibrium (with regard to solute concentration), a mixing element for creating turbulence in the mixing/detention chamber, and suitable tubing for carrying the pumped blood to and from the patent. Methods for utilizing the apparatus are also disclosed.