Easy CO2 dispenser?

Ok, so i had an idea the other day for a somewhat easy sounding CO2 generator...I remember seeing a valve type thing that would screw on to the top of 12 gram CO2 catridges(for BB guns etc), it came in a box of "easy whippets" hahah.. So i was thinking, if you had a small valve that you could screw 12 gram CO2's in to, and then place it under water to open it enough just to allow a small flow of bubbles to come out, or how ever much, and then just place it in a grow room? I'm going to be growing in a 3ft x 4xft area, and i think if i picked up a box of theses, and figured a release valve system, it would be easy and cheaper than CO2 generators to supply CO2 to my closet....any ideas?

Sounds good. The thing is called a cracker. You can buy them in plastic or metal, I would recommand metal , the plastic ones break very easy.

I tried that a few years ago. It is actually cheaper to rent a cylinder and buy co2 in quantity. Those small co2 cartridges leak of in a matter of minutes. You could easily use 10 or 12 in a days time. before long you will have a mountain of empty cartridges. hope this helps!

You can get a 2L bottle, drill a hole in the top, and attach some 1/4" vinyl tubing or something of the sort using silicone. Add like six cups of warm water, 1 cup of sugar, and a teaspoon or two of yeast. Just dump out about half every week or two and replace with sugar water. The yeast cells multiplying produce plenty of co2 which comes out through the tube, really cheap way to increase co2 levels. I used to do this for fish aquariums with lots of live plants. You'd probably want to put the end of the tubing near the top of the plants if you do this, since I'm pretty sure co2 is heavier than normal air.