lol, isnt that a lil too much? i dont ever think ill have a large enought tank for 5. maybe an aro pond one day.
I had 3 in my 600. They varied in size, 23",12" and 9-8" and that looked like the right amount of space for them to swim and grow into.
I would not want to imagine 5 or more.
IMO, don't do it. It sounds like a cool thing now but once they start to fight and one gets hurt or even killed. You will wish you never did it.