This 20 gallon column style background was constructed entirely from scrap pieces of styrofoam. With at least seven previous background projects, the scrap collection was getting rather large.

Scrap pieces were stacked, then secured with bamboo skewers, then shaped with a hot wire to create an impression of natural occurring erosion.

As in previous projects, the aquarium was positioned on its back to ease the application of cement between and behind the columns. With this particular project, there's quite allot of cement applied directly to glass. The liquid acrylic used in the cement mix helped insure a strong bond to the glass.
This step is always satisfying since it hides all the "non-aesthetic" aspects of the background.

As always, it's important to cover everything you don't want painted including the bottom trim of the aquarium. Even painting black over a black trim can later result in unwanted marks on furniture if, for example, an old dresser or chest is used as an aquarium stand.
Flat black enamel paint has been applied here. One trick I sometimes use is to tear small holes in the newspaper over each hardware compartment and shine a light down inside to see any spots that may need a little better paint coverage. This works best in a darkly lit room.

Once the aquarium is up and running, any areas around the hardware compartments with thin paint may allow light thru which could be a visual distraction.
Removing the paper template reveals the painted curve that follows the edge of the background inside the glass.
Artificial Amazon Sword plants seemed to work best with this vertical themed background.

Hidden in the shadows of the background are a heater on the left and H.O.B style filter on the right. The filter returns water over the top of the background for optimal water circulation.
This 20 gallon background was made almost entirely of scraps of polystyrene left over from previous projects.
Having already completed more than a few of these backgrounds, my scrap collection was getting a bit large. It was a good feeling to recycle.