The purpose of this study is to validate the concept of adapted automated PD a modified Peritoneal Equilibration Test (PET), will be performed in children on chronic PD. Instead of a single 4 hour standard dwell, two double mini PET using the same type and total volume of dialysate and the same total dwell time (150min) will be performed in randomised sequence. An double mini test consists of two identical dwells, reflecting routine PD, the other one of a short small dwell followed by a long, large dwell as suggested from adapted PD regimes successfully applied in adult PD patients.