Here's the view from inside:
This should afford a good view of the ham hams running on the saucer/wheel thing and coming/going through one of the tubes. Not ideal, but the best view available.
Meanwhile, here's the algae bioreactor so far:
Needs 18 bottles total (and algae) to provide enough oxygen for 3 hamsters with a reasonable excess to ensure it's sufficient. Guess I'll be drinking a lot of soda for a while.