I am working to start my first biosphere to keep myself occupied during the day
and I have a couple questions on what I should be adding to it.

I can not decide on the number of plants I should add to my biosphere, Does
anyone know about how many leafy plants (please include sizes of plants in your
answers if possible) should I add for every, lets say, cubic foot of soil?

Also, Would I be okay with only bacteria and plants in biosphere or should I add
a few critters to help balance out the O2 CO2 etc. levels.

Thanks