The invention relates to an apparatus for preparing a peritoneal dialysis solution at the point of use comprising a disposable having a solution bag and associated filling lines and patient lines； a storage unit for liquid connected to the filling line； a control unit； and actuators for regulating a flow from the storage unit to the disposable, wherein the apparatus furthermore comprises a scale at which the solution bag of the disposable is arranged, with the control unit being configured to initiate a filling of the solution bag with liquid from the storage unit using the actuators and to determine the quantity of the liquid that has flowed into the solution bag using the scale.
