We have a 45 gallon terrarium and it isn't meant to be filled with water. But it is doing just fine with 5 gallons of water on one side.
:thanks for the info. the owner said that it cannot hold any water since it is a terrarium. it has no cracks that i can see. also, there is a label on the tank saying that it cannot hold water. well, we'll see about that. i recently took off the silicone that was originally on it with some razor blades. then i put some new silicone around it and a piece of plexi that goes in the middle to make it 50% water and 50% land. also, i made it so that only about 5" of water can be held by the water half of the tank. i'll let you guys know how it turns out. thanks!