That is a very cool aquascape. I think it all looks natural with the exception of the one red rock sitting up on the driftwood that draws the eye straight there. I would try swapping it with the round brown rock in the foreground to lighten up that area and to draw the eye to the triangle created by the driftwood. I think the red rock would look nice shrouded in those round leaves under the driftwood and tie in better with the other red rock you have in the foreground. It is a very nice aquascape though and i love your fish. I like the tank with the full light or the setting in the sixth picture.