Systems and methods are provided for conveying an amount of red blood cells and an amount of plasma to a blood source. Blood is conveyed from a blood source into a separation device and the separation device is operated to separate the blood into a layer containing red blood cells and a layer containing plasma. Red blood cells and plasma are removed from the separation device and volumes of the red blood cells and plasma are conveyed to the blood source. The volumes of red blood cells and plasma are alternately conveyed to the blood source for said amounts of red blood cells and plasma.