I base my tub size on size and personality only, not age. What I mean by personality is that some animals are just more comfortable in tighter spaces than others, so those do not get moved up as fast.


Corns

Sandwich box for neonates
8 qt shoebox up to 25 to 125g
15 qt for 125 to 200g
27 or 32 qt 200 to 300g
300+g get a 41 qt.

I have one girl that is pushing 1000g....she is getting close.

Still working on my BP weights / tub