The invention relates to a device and a method for conveying a fluid to a filter unit of a medical treatment apparatus, in particular for conveying a dialysing fluid to a treatment unit, in particular a dialyser or filter of an extracorporeal blood treatment apparatus. The device comprises a balancing unit and a recirculation unit, which comprises one or more chambers. With the balancing unit, it is possible to supply fresh fluid continuously to the recirculation circuit and to discharge used fluid from the recirculation circuit. The supply and discharge of fresh and used dialysing fluid can take place at a flow rate other than the flow rate at which the fluid circulates in the recirculation circuit via the filter unit.