Hi guys!! I'm new to this forum. I decided to join because I've heard from a lot of people that you guys know a lot about constructing terrariums! I plan on building a 500+ gallon terrarium, not for dart frogs, but for my hermit crabs! Crazy, right? Lol. It will have 24 inches of substrate (Play sand + Coco fiber) w/ a false bottom, of course. The tank will be approximately 48x40x70. I plan on using interior oak plywood, waterproofed (on the sides exposed) w/ aquarium epoxy and pond liner. I will also be using 2x4s (waterproofed as well) to construct a frame to support the weight that will be put into the enclosure. Hermit crabs live in tropical environments so the temp will be in the 80s along w/ the humidity, at all times. So I'll need to get some heat bulbs, possibly some heat cables, and automatic misters. I will be using crab safe plants such as parlor palm seedlings, ponytail palm trees, etc. The background will be made w/ Great Stuff Foam & Cork Bark. They'll be multiple levels made from the waterproofed plywood. For easy access & viewing, I plan on putting an opening glass door on the front. There's a lot more planning that needs to be done, but that sums up most of it. PLEASE give me any input/advice you may have. I've never done something like this before so it'll definitely be a challenge. *CONSTRUCTIVE CRITICISM IS WELCOME!!!*