I have pretty much the same configuration you have -- a 72" tank divided in two. I cut plexiglass to size and sealed it in place with silicon caulking. It works great, and I've left the space between the two beardies open because I like the open look of it, and they don't seem to mind each other's presence much. If they do decide to get grumpy with each other, it would be easy to cover though. I think the two spaces side by side look really neat, like little beardie apartments. When I get home tonight I should post a picture for you, including a close up of the hopelessly unprofessional caulking job. Plus, I had a devil of a time cutting through the plexiglass, and ended up with shards on one edge that needed to be sanded down with a rotary sander.