Natural would be no filtration. A tank, lights, and a pump to move water. Nothing else. It is doable. You won't have a clean looking tank. There will be algae and it won't be "pristine" like a lot of the tanks you see on here.
That's what I have, no water changes, I have plenty of macroalgae growing that does the job, never fed the shrimp or fish in the. It's its own eco system
