CO2 is such a game-changer. I'm kicking around adding it to my 2 Dennerle tanks in the office but small tanks get tricky injecting off of one controller. And add in 0 KH and aqua soil (and fragile Caridina), and it would really take some dialing in. But I'm getting a year's worth of low-tech growth in these two each month, and with very little in the way of algae issues. It's a monetary investment and the set up and dialing in is certainly some work, but it sure is a shortcut to lush growth and good colors. I pruned off 12" strips of Anubias in this one last night. I can't guess how long such Anubias growth would take in low tech.
Nothing good happens fast in an ecosystem.