Originally Posted by Cory
Did I induce this?
I used 3/4 ply for the whole project and think it gives the stability needed for long term life. Its around 400 gal and two people can carry it.
400 Gallons is a monster! 8) If you are going to have a substantial amount of water in the tank (like 1/3-1/2 full of water), I would agree that 3/4 inch plywood is in order.
However, I have seen 400 gallon plywood aquariums built from 3/4 inch plywood and 1/4 inch glass that were 10 years old. We don't put nearly that type of structural strain on a terrarium, and I personally think it's overkill in a terrarium. If you plan on keeping the terrarium in one place and have no concerns about moving it, then that is no big deal.
However, since Dane indicated that his design is going to be modular, I am guessing that he may be considering portability at some point in time. My 1/4" ply tanks are soooooo much easier to move around than my original tank, and they are the same size.
My original tank is the epitome of overkill: 3/4" ply for the bottom, 2x6 dimensional lumber for the bottom sides, 1/2" glass, and 1/2" plywood back. I cut down an old hinged glass shower door for the top, and used aluminum "u" channel for the sliding glass front. One person can pick up the tank . . . but it's a workout.
Edited to add this:
P.S.--Cory, we want to see some pics!