A generalized kinetic model to quantify the efficiency of cycler (CPD) and tidal peritoneal dialysis (TPD) is used to examine the relative efficiency of these techniques over a wide range of tidal volumes, drain profile characteristics, and hourly dialysate flow rates. In the patient with good catheter function, there is little difference in efficiency between CPD and TPD. In patients with long drain times or nonlinear drain profiles, greatly improved efficiency may theoretically be achieved with small tidal volume TPD. A generalized solution of the continuous flow PD (CFPD) kinetic model is used to demonstrate and contrast the kinetics of automated PD (APD) and CFPD.