Let me make it really easy on you... get 2 cups one bigger than the other.. in the smaller of the two put a small amount of vinegar prolly about an inch deep (if your using a 16oz and a 12oz red party cup, put a bit of vinegar int he 12oz) then put the larger cup inside of the smaller cup, so that its bottom isnt touching the vinegar directly... take it out, now take that bigger cup and poke a hole in it, put some yarn thru the whole (enough to dip into the vinegar, preferably to the bottom of the smaller cup) and tie a knot at the top so it doesnt slip the the hole you poked.. now put baking soda over the yarn knot and all the bottom of the larger cup, the vinegar will wick up the yarn and into the baking soda... and voila a steady source of co2 (enough for a small closet grow) and it lasts a decent amount of time...(if you bought a bottle of viengar and a box of baking soda that will last you years most likely) hope this helps