disposable c02 dispenser

has anyone seen anything like this at their grow store? i Always see veteran growers at the hydro store buyin these in 2 or 3's, wonder how well it works. must be good for 40$ each every 2 weeks.


http://www.valleyindoor.com/product.php?productid=1080&cat=94&page=2

comes in 2L bottle.

I couldn't find any information on how they work, but the directions say to add warm water, shake, and it will disperse CO2 for up to two weeks... which makes it sound like it's just a small yeast/sugar generator in a 2-liter bottle. You can make your own (better) very easily and for *much* cheaper. $40 every two weeks would equate to about $300 just to get through the flowering period of a single grow (and without using one at all during vegetative growth).

IMO, that's crazy expensive for what you get! You could buy/rent a real CO2 generator or large canisters for that amount of money and have better results.

My advice would be to buy a CO2 regulator, a tank and a digital timer. It will be more cost effective in the long run.

or check this out...
https://www.rollitup.org/newbie-central/343918-myth-busters-real-truth-co2.html