I don't use any backgrounds for my reefs.
My 42 gal hex is located in the dining room with three windows around it. The 72 gal bowfront is in front of a large window in the living room. All windows are facing east. In summer, I keep the blinds closed in the morning but open them in the afternoon. Spring, winter and fall, the blinds are open all the time.
Love that free light
72 gal with blinds closed:
72 gal with blinds open:
