You are right, they can sometimes do the "Triple Lindy" and hit the floor and that is tragic. You could try and use the method that Gary M used on the top of his tank...some kind of nylon grid that does not inhibit light at all and would prevent jumping...you could pm him on that, im sure he would explain. I'm planning on moving up to a 120 in the near future and my incorporate this on my new tank.
Geo
Geo