My two whites live in a 50 gallon vivarium that we made without using a single piece of glass. we picked up some verigated plastic from home depo, non-toxic silicone, some plants, organic soil, and an old cuboard from a garage sale. we kept the cost for the whole thing (excluding the frogs) under $100. we simply made a kind of insert with the plastic, and secured it into the cuboard, making sure it fits tight to the door to pervent the escape of crickets! the bottom has a little wall in the front to keep dirt in and just in case the water spills. we planted the plants and mounted the light fixture, the let it grow for a month to get all the fertalizers out of the plants. I've never had a problem with it (up and running for about a year now) and the humidity stays at the perfect level. unfortunatly we didnt take photos while we were building it, but i can take some more of the sides and the light at the top later and i'll post the ones i already have loaded.
~hope i helped!

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0.1.0. Leo
1.1.0. WTF
0.1.0. Irish Setter
2.2.0. Holland Lop Bunnies
1.1.0. House Cats
Too Many Fish!