I read that it's possible to produce an adequate amount of C02, for increased growth, by putting yeasts in sugar and water. At least this guy is making that claim on ebay http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=2003900627 Do you guys think that would work? If so, that's a hell of a lot cheaper than buying one of regulation systems.