The present invention relates to a balancing unit (100) for medical fluidscomprising at least one balancing chamber and at least one conveying means forfilling the balancing chamber, wherein the conveying means is a pressurecontrolled conveying means and/or is designed and provided for being operatedinat least one operating state as a constant-pressure source. The presentinventionfurther relates to an external medical functional means (200), a treatmentapparatus (300) and methods.
