Tony
Alligator Snapping Turtle/Past Pres
If I were to add plants, I would need to buy a CO2 injection system right?
While it doesn't hurt, it is so very far from necessary. I have one high-tech planted 45 gal tank with CO2 and one low tech planted tank without. While the CO2 makes plants grow like weeds (in addition to supplements, under-gravel heater and big lighting), the plants in the low-tech 20 do just fine (anubias, java fern and crypts). you definitely would not want to do it with Africans as it drops the pH somewhat, depending on the GH of the water.
I also keep anubias in almost every tank in the house. My 110 mixed mbuna and hap tank has large groves of it. I keep a piece in every one of my African tanks on my rack as well. The fish will occasionally chew up the brown/yellowing edges of the plants, but leave it alone for the most part.
As a matter of fact, the low-tech planted 20 I was talking about above with the java fern and crypts is inhabbited by 6 juvie demasoni, lol. (I know I'll have to move them eventually, but they're doing fine for now and the wife loves them in her tank.)
And that's coming from an African keeper. If I kept more new world, plants would be coming out of my ears.