If you're having any problems, it may not be with the gas exchange, it may be the humidity.

If you're using perlite as your form of humidification, what can happen is that when you fan out your terrainum you're fanning out the humidity. And with perlite, it can take anywhere between and hour and 3 hours for your humidity levels to raise back up to where they should be.

hope that helps:-)

My problems arent with humidity or O2 levels. I simply forgot to recover my terranium this morning and was curious if 6 hours of 02 contact would be harmful.

And if contaminants could take over.

But sounds like they should be okay. They are growing like mad men.