Jason,
I too am somewhat new to apistos. I'm up to 20 tanks. I started with the 30 longs that you describe but, I found it was kind of a waste of height. I mainly use 20 longs now with divider. When fish breed or are raising fry I try to give them the whole tank if possible. I do have a 55gal planted tank but, my breeding tanks are bare bottom. As for the CO2 I too use the DIY yeast injection and what the krib has to say is pretty good. If you need more info I would check out the Plants mailing list here's their link.
http://www.actwin.com/fish/aquatic-plants/index.php
Hope this helps....
-=JerryB=-
JerryBsApistoWorld "Life is What happens when your busy making other plans"