I have an idea about a tank I would like to attempt and was hoping for some criticisms before I start it. My goals for this tank are mainly low maintenance (no more than 1x/month water changes) and cheap (ideally free).

I have an empty 10g tank I would like to try this with...

Plants:
Half or 3/4 full tank with no hood - growing as many low light emersed plants as I have available such as java fern, anubias, hygrophila, and I'm going to try a terrestrial plant native to bogs that I happen to have, that will grow roots in the water with leaves sticking up out of the top of the tank. My hopeful idea is that the plants will reduce nitrates sufficiently to avoid having to do too many water changes, while being tolerant of lower lighting and thus reducing the propensity for algae growth.

Light:
Only indirect lighting from a north window - eliminating some of the algae issues by limiting light more drastically. I can adjust this if needed by adding more artificial light or reducing it.

Substrate:
I don't have access to a lot of options here....crushed shale is in abundance here and perhaps would provide some enrichment? Some larger pieces of shale could serve as hardscape.

Filtration:
Just plants....plus a submersible pump just to add circulation.

Stock:
An oto or two for algae control, and one or two female bettas or maybe just one male betta.

Fertilizers:
Initially, all macros, Plantex CSM+B, calcium chloride and magnesium sulfate. Following up, on an as needed basis depending on how things go. My tap water is nearly 0ppm on just about everything as per the town analysis so I'll need to add pretty much everything the plants will need. I don't know if KH would be necessary though..?

This is a little similar to the "el natural" idea...I have attempted this and it ended with serious algae infestations. I didn't seem to have enough plants, the plants didn't seem to be healthy enough, and I think the soil substrate leaching ammonia contributed to the algae problems that eventually caused the tank's demise.

Any thoughts before I proceed?

Well...I set it up as planned, but with no stock yet. Just letting the plants get established and then I plan on testing to see what the NH4 uptake will be....gives me an idea of the stocking it will be able to handle.

Very nice. What about a newt or two for residents? Maybe a small surface predator or two?

Very creative and unique -- I like the looks of it. Keep us updated on how this works out. I might try something like that.

Thanks!
Since there's not really much "dry" ground there, and no heater or filtration to speak of, I was thinking of maybe three white clouds. I'm seeding the tank with ammonia starting today, to see what the uptake might be with just the plants with no cycling action, and give me an idea on whether I can stock it yet or how heavily I can stock it.