Well, light, co2 and ferts all sort of go together, if you increase one, you often have to increase the others too. So, thats not the easiest question to give a solid answer for.
However, I have both Amazon and Argentine sword and I do not use ferts/co2/ or have very good lights and my plants flourish.
Be warned though, both of those sword species get rather large. Argentine swords (which is still what I think this is) reach 18 inches and Amazon swords (which I still think this is not, but I have been wrong before) reach like 2 feet.