so, on my 20 gallon long i figured out the light thing. I wasnt going to get a new one, but my current one flickers and shuts off several times a day. Its annoying and the fish seem to think its a thunderstorm or something. Going to get a fluval 3.0 today. I'm wondering now about CO2. my plants seem to be growing like weeds already. i dose excel and flourish, and use iron for my rotala and ludwigia. And a bunch if root tabs. But some of them still don't seem to happy. What's a good CO2 set up and how does it all work/were can i get it?