I, too, have bouts of ascites. To relieve the pressure in my abdomen from the fluid build-up, I have gone through 2 "therapeutic" paracentesis procedures (1st one removed 5.4L and 2nd one removed 6.0L). Although the procedures caused stomach pain, the pain went away as my body re-adjusted back to its semi-normal state, dropped 11 and 13 lbs., respectively, and don't feel the constant pressure. My weight has now remained constant from the 2nd procedure done on 12/07/12 so I'm remaining hopeful that it continues to do so!
Many thoughts and prayers to your dad and you, Smferlita!