Tub Dividers?

I have Sterilite 28 qt tubs and I'm looking for dividers. I've seen the ones that reptile basics has, but they won't work for me.

Anybody have any DIY ideas or purchased anything that will work? Anybody found any tubs in the 15qt range that has the same height as a 28 qt?

caulking with some clear plexi glass cut to fit may work, just allow it to dry then put the snake back in.

I used some styrofoam poster board wrapped in glad press-n-seal with hot glue to divide some of my tubs. It seems to be working pretty well so far, but it's a permanent divider.

I was trying to figure out a way to do that myself with the styrofoam poster board. If you cut it and glued pieces on to make it in the shape of an I, you could put that in your tub and it should hold up. I'm not sure how well it would hold up to moisture though.

12 qt sterilite bins are really close to the same height as 28 qt bins.