[takluyver]

It appears that you don't have much carbon, though (see 'Lunar regolith' on Wikipedia). So once you've got your oxygen generator set up, you may have to fly coal up there to burn for CO2. Once you're set up, though, you should be able to keep the carbon in a closed loop between humans, the encapsulated air and the plants.

[danielweber]

It's hard to grow a colony if the things people are made of has to be imported in.

The far side of the moon is awesome for science (the most ultimate radio telescope ever) but not so much for growing humans.

[mogrim]

Didn't realise that, although beyond reading pulp SF, I've not done any kind of investigation into the subject!

How much carbon/coal would you need to support a colony of say, 5 people (+plants)?

[takluyver]

If the plant material to support each person is drawing down 2 moles CO2 per hour (doubled from earlier calculations, because not all the carbon ends up in edible parts), then a tonne of carbon should supply the plants needed for 5 people for a year. By the end of the year, you've probably closed the loop, so the fixed carbon is returning to the air.

[omegaworks]

Soylent green is people!