Well, I finally decided to give CO2 a try in my 29-gallon planted. Currently I'm running one bottle (that was all the sugar I had) through an airstone. When I first set it up it bubbled for all of about 30 minutes and quit, but I added some more warm water, shook it up, and it took off. It's been going for about 4 days now, and the bubbles are slowing, but for a first try at least its working! Should I shake it up or something to keep it going good?