setting up a 70-80 gallon terrarium

[thefish1337]

I recently acquired an old laminar flow sash hood that was going to be thrown out. It was once used to inspect mail for things like anthrax during the 2000s. The actual fan is broken but the hood had me seeing terrarium dreams. I will use this post to document the progress I make in converting this into a terrarium. The front opening is excellent for working inside but also seals well. The demensions are 34L X 24 W at the base and 34" L X 18" W at the top and 23" tall.



The main thing I want help with ideas for is the bottom. I was thinking about making a liner that contains about 2-3" of substrate. But I'm also curious about going substrate less since I plan on only having epiphytes. Next I will focus on lighting. Is it possible to create a gradient where i can grow high light plants from the middle to the top areas but low light plants at the bottom?