If you pick a suitable selection of plants, they can look vibrant with proper lighting, fertilization, and without injected CO2. For some inspiration, check for example the recent videos of MD Fish Tanks in youtube. If your goal is to have faster plant growth and specific plants (such as dense carpet plants) then you need to consider CO2. If not you will be throwing money away buying and trying to keep plants that will struggle in a low tech setup (like the HC Cuba). But it will always be more expensive to add CO2 injection to this tank than to keep it without CO2 because of the extra equipment and running costs (which are not insignificant).The realisation that my plants don't look as vibrant as I want them too after x amount of time and money!
What @Siege says, just let the plants grow in. Have a look at the <"Seasoned tank time"> concept, basically a "seasoned tank" is what you want before you add any fish.Seen so much on fish in cycles and have read up on how to do them. .......... Happy to be told otherwise though
providing this is just melt, and not a disease will the rhizomes grow back?