Just getting good coralline growth now as have solved a brown algae problem--heat problem.
If I leave the back alone, and remove the paper background scene, there will be a significant amount of light enter from the back. No coralline on the back at present, but the brown algae does settle there.
Also all of the wiring/tubings will be exposed if I leave the back clear, at least until coralline takes over.
Would have to dismantle to use a spray paint.... not an option.