@Viva_Mexico not at all, I just keep it going. Plants don't uptake CO2 at night right, but i've seen no harm. What I do is giving additional fresh air at nights so I think this balances levels straight.
@MicroDoser Maybe sugar is more expansive than CO2, but you haven't read closly. I use the alcohol for distilling, so I need it either way. If you don't need alcohol, go on with your Bottles...
But also two things to consider: If you live in a state where pot is still illegal people will be curious what you bring into your flat... Also, these bottles are a lot heavier then bringing a few kilo sugar/yeast into your flat..
Pest control argument is also bullshit, you don't have any pests when doin it right with an airlock..