Andrew circulation is not needed w/ a water table. Is this water table going to be built into the bottom of the table? If so just use compressed air to push water out of the "bladder" up to the table. Very effecient and easy to do. I am going to try and attach a .pdf of a concept for a water table. This was the way I did it - and I love it. My table fills and dumps pretty fast and catches about 95 -98% of the plasma smoke. I generally run with my water no further than 1/4" from the material or even touching the back.
I found this .pdf on Jim Colts yahoo forum several years ago.