A method, system and apparatus for performing peritoneal dialysis are provided. To this end, in part, a pump for a dialysis system is provided. The pump includes a first chamber wall including a first aperture, a second chamber wall including a second aperture, a piston, at least a portion of which can move through the second aperture, the piston including a third aperture, and first and second membranes disposed between the first and second chambers walls. A vacuum can be applied through the first aperture to pull the first membrane towards the first chamber wall and can be applied through the third aperture to pull the second membrane towards the piston. The piston can thereafter move the second membrane.