[Michael Hoaster]

You are welcome! I agree, no need to spend cash on the temporary setup. Save it for the big show! As for CO2, that's up to you. You don't have to supplement it. Injecting CO2 just makes it easier to have success with plants. Without supplementation, plants grow slower, since they have to work harder to find available CO2 (or bicarbonates). I would think there is a way to test CO2 levels.

I think you are good to go, using local substrates. They probably have everything grasses and macros need. I think it gives you an edge, having a natural substrate that is already 'seasoned'. I have to buy the clean stuff, and add dirt and mud to season it.

Starting up the big tank, I'd advise you plant heavily, to outcompete algae and to see what does well for you. If you have a local grass, you might give it a try. Or maybe you have a favorite local macro. Research the needs of the plants you like and try to provide as ideal conditions as practical.

It really takes a committed effort to grow plants. So far, you have not had much luck with plants. What do you plan to do differently?

Then, the focus changes as your tank matures. First the focus is substrate, then plants, then other inverts like tunicates, then fish. Each stage supports the next, from the bottom up!