Anyone use these? I'm thinking about trying it. https://www.google.com/search?q=co2+bags+growing&hl=en&safe=off&client=firefox-a&hs=jj2&tbo=u&rls=org.mozilla:en-US:official&source=univ&tbm=shop&sa=X&ei=MoetUMCNG4nkygGt6IDACA&ved=0CJsBELMY&biw=1920&bih=1047