It takes a really long time to grow a hatchling to 2000+ grams. 28qt tubs are fine for snakes less than 2000g. I would build a rack that holds X number of 28qt tubs since two 12qt tubs fit in the same space as a 28qt tub you could use smaller tubs for babies and upgrade as they go. Either way buy all the tubs first and s=make your rack specific to those tubs. Lots of tubs can vary (as I learned the hard way).