@NathanG - I’ve never seen the movie, but I think it was based on the real life Biodome 2 experiment in Arizona, which was no less successful. The biodome started out good, and was full of many different types of plant life, animals, algae, etc. However, it ended in failure (in my opinion) because the oxygen supply dropped to very low levels.
It got so bad that they had to pump in oxygen from the outside, which is ironic when you think about it. It defeats the whole premise of the biodome, which is that of an artificial environment that can sustain life.
Many theories have been put forward as to why the oxygen levels dropped, some advancing the idea that it had to do with the microbes in the soil. I’m not a scientist so I don’t know. I just think there are more variables in the environment than we realize.