Hemodialysis system including a disposable set and a dialysis instrument

A hemodialysis system comprising:

• a dialyzer;
• an online dialysate generation system including:
• a water inlet line, and
• a drain line;
• a disposable set including:
• a supply tube fluidly connected to the online dialysate generation system, and
• a dialysate pumping tube fluidly connected to the dialyzer;
• and
• a dialysis instrument including:
• a dialysate pump head,
• a motor positioned and arranged to operate the dialysate pump head, and
• an interface for receiving the disposable set to enable the disposable set to be loaded into the dialysis instrument such that the dialysate pumping tube comes into registry with the dialysate pump head,
• wherein the dialysis instrument operates the dialysate pump head to move fresh dialysate from the online dialysate generation system through the dialysate pumping tube to the dialyzer.