An extracorporeal blood treatment apparatus comprising: a blood circuit that includes an arterial line intended to draw blood from a patient and a venous line intended to return blood to the patient; and a treatment solution delivery system configured to deliver treatment solution within the blood treatment apparatus through a treatment solution port, wherein the treatment solution delivery system comprises: a plurality of treatment solution reservoirs (11, 12), wherein each treatment solution reservoir (11, 12) of the plurality of treatment solution reservoirs (11, 12) comprises an outlet; a tubing set comprising a junction, a plurality of feeder lines (61, 62) connected to the junction, and an outlet line connected to the junction, the tubing set configured to deliver treatment solution from the plurality of treatment solution reservoirs (11, 12) to the outlet line through the junction; a reservoir status monitor configured to determine when a treatment solution reservoir (11, 12) of the plurality of treatment solution reservoirs (11, 12) requires replacement; an output flow controller operatively connected to the outlet line, wherein the output flow controller is configured to deliver treatment solution from the plurality of treatment solution reservoirs (11, 12) to the treatment solution port; and a control unit operably connected to the output flow controller, wherein the control unit is configured to operate the output flow controller; characterized in that the treatment solution delivery system further comprises: at least one liquid-gas separation filter (71, 72) positioned in the tubing set, wherein all treatment solution passing through the outlet line passes through the at least one liquid-gas separation filter (71, 72), the at least one liquid-gas separation filter (71, 72) including hydrophilic media through which liquid passes and a hydrophobic membrane configured to provide a vent for gas separated from the liquid. a blood circuit that includes an arterial line intended to draw blood from a patient and a venous line intended to return blood to the patient; and a treatment solution delivery system configured to deliver treatment solution within the blood treatment apparatus through a treatment solution port, wherein the treatment solution delivery system comprises: a plurality of treatment solution reservoirs (11, 12), wherein each treatment solution reservoir (11, 12) of the plurality of treatment solution reservoirs (11, 12) comprises an outlet; a tubing set comprising a junction, a plurality of feeder lines (61, 62) connected to the junction, and an outlet line connected to the junction, the tubing set configured to deliver treatment solution from the plurality of treatment solution reservoirs (11, 12) to the outlet line through the junction; a reservoir status monitor configured to determine when a treatment solution reservoir (11, 12) of the plurality of treatment solution reservoirs (11, 12) requires replacement; an output flow controller operatively connected to the outlet line, wherein the output flow controller is configured to deliver treatment solution from the plurality of treatment solution reservoirs (11, 12) to the treatment solution port; and a control unit operably connected to the output flow controller, wherein the control unit is configured to operate the output flow controller; characterized in that a plurality of treatment solution reservoirs (11, 12), wherein each treatment solution reservoir (11, 12) of the plurality of treatment solution reservoirs (11, 12) comprises an outlet; a tubing set comprising a junction, a plurality of feeder lines (61, 62) connected to the junction, and an outlet line connected to the junction, the tubing set configured to deliver treatment solution from the plurality of treatment solution reservoirs (11, 12) to the outlet line through the junction; a reservoir status monitor configured to determine when a treatment solution reservoir (11, 12) of the plurality of treatment solution reservoirs (11, 12) requires replacement; an output flow controller operatively connected to the outlet line, wherein the output flow controller is configured to deliver treatment solution from the plurality of treatment solution reservoirs (11, 12) to the treatment solution port; and a control unit operably connected to the output flow controller, wherein the control unit is configured to operate the output flow controller; characterized in that the treatment solution delivery system further comprises: at least one liquid-gas separation filter (71, 72) positioned in the tubing set, wherein all treatment solution passing through the outlet line passes through the at least one liquid-gas separation filter (71, 72), the at least one liquid-gas separation filter (71, 72) including hydrophilic media through which liquid passes and a hydrophobic membrane configured to provide a vent for gas separated from the liquid. at least one liquid-gas separation filter (71, 72) positioned in the tubing set, wherein all treatment solution passing through the outlet line passes through the at least one liquid-gas separation filter (71, 72), the at least one liquid-gas separation filter (71, 72) including hydrophilic media through which liquid passes and a hydrophobic membrane configured to provide a vent for gas separated from the liquid.