I really love this whole set up as well as your adventure. It just looks...............fantastic!
The good news is I know my wife will make me get it done before Christmas so I have high hopes!I might have missed it somewhere, but I never saw how many gallons it is.. Man if I had that setup, I would have one male marble motoro in with like three females, and make some money!!!

How bad is the evaporation with the water fall? Managable or are you replacing water daily?
Not bad at all, I never see the water line between my weekly w/c as long as I fill to the lid when filling up (about half way up the trim). I was worried at first when setting it up that I would have to top off during the week but that's not the case.
Ok great, thats a similar situation I have with one of my tanks.....Helps remind me to stay up on my water changes....if I start seeing the water line then I know Im behind and need to get it done