does anybody remember sience class? Remember making paper mache volcanos with the bicarbonate soda and vinager? well heres how it works. The reaction of baking powder (bicarb) and vinegar is used as an example of an irreversible reaction.
The nature of atoms and molecules is touched on enough to explain the reaction - how a solid (bicarb) and a liquid (vinegar) combine to make a gas (carbon dioxide).

Moral of the story get a container make a mini volcano in it in you growroom. Doing that once a day should do the trick!