My terrariums usually bit the dust after a couple of years. I noticed he used compost, not potting soil. As one of the commenters said, there were probably lots of nice micro-organisms in that compost. I wonder how long it would last with a little animal in there, like a little salamander. Hmmmm....(brain working feverishly)....OK, I won't try it. A betta in a vase with a peace lily is about as far as I will go, I guess, lol!