one way is to have a post that is firmly held in place.
then put a plate on top to hold one part of the bearing.
a second adapter to hold the other part of the bearing and your PVC tower.
at the bottom some way of centering the tower on the tube. if you use the inside as a water return, then the lower part only needs to have holes to let it drain.
mechanics.
the next question is how and were to mount the motor and where and how to connect the water line.
