Yes, there is a backing. About a quarter of the tank is in front of a window, but the window is completely underground so the sun rarely reaches the tank.
well I recently rescued some fish from someone so some tetras don't have a full schooling group yet. 4 Corydoras, 1 Cherry Barb, 1 Balloon Belly Molly, 3 Guppies, 1 Lemon Tetra, 2 Black Neons, 2 Black Skirted tetras, 5 Glow Light Tetras, 5 Bleeding Heart Tetras, 8 Neons, and 2 Dwarf Frogs
the only reason chelbel was asking about the window was cause if any part of the tank is in direct sunlight algea will grow like crazy, but if you have had the tank in that location for a while and havnthad any problems with algea you should be fine