Nice one, this looks brilliant. Good to see that you did set up and scape another tank.
I kind of like the little bit on the right, perhaps it would look better a little further back with some taller plants behind in the back right corner?... But I'm no expert.
I had a DIY yeast CO2 system a while back, I didn't like it that much, because it was single 'canister' and changing the mix every week made the CO2 too vaired throughout the week. How have you set yours up?