RodMad,
Great to hear your training has been going well. I'd love to see some pictures / videos of Russell if you've got them! Has he learned to fetch the ring? That one is my favorite, and one of the most difficult to master (for fish and trainer!).
Regarding the overhang on most tanks - the way I found to avoid the problem is to have the water level a little lower in the tank, so the overhang doesn't interfere with the motion of the ball. You can see this in the short basketball segment in the video on the website:
http://fish-school.com/
> Also, does anyone else have to shut down their filter while teaching
> this trick
Yes - it definitely helps to shut off the filter for the basketball trip, to keep the ball from drifting due to the circulation of the water.
Take care!
--Dean