Tub Sizes and Racks

This has proly been done before... but I'm looking to switch my two bp's from their tanks to tubs in racks. One problem may be one is one in a a 7 year old male and one is a little over 8 months and is female. I'm assuming there's way different sizes needed for tubs or would the juvenile be able to stay in one larger one for pretty much... ever? So my question(s) is/are what tub sizes for rack systems work best for everyone? I'd love answers for both juveniles and adults. And my second one if the sizes differ I'm assuming the racks would be different, as well?
Thanks, everyone!

I have a 6qt rack that I use for hatchlings but when I get down to only a few hatchlings I just simply set the smaller tubs up in my 28 qt rack. I just be sure to use a lid and secure it. Monitor the temps and adjust how much of the tub Is on the heat tape accordingly. Depending on your tub size you are going with, an 8 month old ball will probably be ok in the adult tub. I have 300 gram balls on 28 qt tubs and back when I used cb70 tubs for dwarf Boas, I had 500-700 gram balls in the same racks and they thrived.
From my experience most will do fine in a larger tub granted they feel secure. I never use hides, just an extra thixk layer of aspen. Hope this helps a little. Just my experience

It does help, thank you! But for the tub size themselves what are you using for adult tubs?

I use 41qt for large Females. Anything up to around 2000 grams stays in 28qt. I currently have torn my 41 qt rack down but will be redoing it when I get back from vacation

Thank you very much! It means a lot.

That's just my experience though. It will vary person to person. Collection to collection

I use an animal plastics economy rack that holds 15 qt and 32 qt tubs. I have a year old female in a 15 qt and my 4-5 year old male in a 32 qt. Hope this helps.

ETA, it's the 1753 series. I also have a similar one from Dragons4You.

Thank you very much! And everything helps.