This is my girls 40 gallon (small, ik) bioactive vivarium! Btw, I highly recommend bioactive, it makes cleanup so much easier. Got a few dried out leaves from yesterday? Bury them (so the bugs can have a snack). Beardie had a monster poop? Bury it even deeper (nutrients for the plants). I know you're supposed to have a enclosure bigger than 40 gallons, but I am homeschooled so she is out of the enclosure a lot chilling on my desk or window sill. She seems super happy! Btw, all of these vivariums look so pretty!