Rack Size per snake?

Ok, so here is one for you husbandry/breeder specialists out there. I've done a bit of searching without any exact results, so I've elected to post a questions up here.

I've had my BP in a 20L tank for his entire time with me so far, and I would like to change up to something plastic, but not a tub. I've spoken to Rich at reptile basics, and he advises that a 2'x3' tank is sufficient for even a full size BP. The rack idea looks good, however the likelyhood of me getting more BP's is not very high.

So, if a full size BP needs a 2'x3' tank, how do you keep adult bp's in those reletively smaller racks?

What is the average size in feet and or inches of your adult rack tubs?

Maybe they just seem small in the pictures, i dont know, but before I move on to something else, I'd sure like to peg down how big my snake's new living quarters should be.

Thanks,
-Camp

We have three sizes of racks all from vision. A hatchling rack which is just shoe box sized , V-35's which has tubs that are 20 x 15 x 5.5 and for then the larger females are in a CB-70 which is 34 x 17.5 x 5.5.

Depending on how you do the math and which idea you follow a 2 X 3 tank should be good for up to a 6ft ball.