Ok, I have searched images and cannot figure this out.
I assumed that the toilet was a straight drop into the blank tank. I have a wand that I use to flush the tank. When I drop it into the toilet and let it spin, my clear elbow shows me as expected that its working. Once the water is Aquafina clear, I can twist that wand around and it actually goes towards the drain(black tank exit) in what feels like a short pipe.
Then the clear elbow shows me "stuff" like I haven't even cleaned it!
So, does the toilet drain into a pipe that flows into the black tank?