A method of adjusting a patient's undesired hematocrit and/or hemoglobin concentration to a value within a desired range at a predetermined time with an erythropoiesis stimulating agent (ESA) regimen includes obtaining patient parameters required for input into a model for predicting the patient's hematocrit and/or hemoglobin concentration at a predetermined time with a selected ESA administration regimen, the model including iron homeostasis, and employing the patient parameters and an initially selected ESA administration regimen in the model to predict the patient's hematocrit and/or hemoglobin concentration at the predetermined time with the initially selected ESA administration regimen. The method then includes administering ESA to the patient with an ESA administration regimen predicted to adjust the patient's hematocrit and/or hemoglobin concentration to the desired range at the predetermined time. The method can be implemented in a hemodialysis system.