Im pretty new around here but Ill give it a try. Are you saying your Ball Python and your Red Tail Boa are in the same tanks? I dont think that is a good idea, might not be safe (actually sounds like something bad waiting to happen) but Ill leave that to someone else who knows more about that. But what I do know is that I have a rack for my geckos, that holds 21 15qt tubs. Thats 7 shelves, 3 per shelf. I can easily take out some of the 15 quart tubs and put in 32qt tubs. Then it will hold 7 32qt tubs and 7 15qt tubs. Off the top of my head i dont remember what size the next size up tub is, but if I decided to it could just hold 7 of those. So as you see you can change it with your current needs. I have to say I did personally build this rack so i dont know if the ones that you buy convert so easily. I hope this helps. (BTW, I am new to Ball Pythons so mine are in tanks so I can learn them. So no I havent put them in tubs or my rack.) Here is a pic of my rack if you were interested. (This was before I put the heat tape and the back of it on.)