Often times when I browse the Internet to look for people's tank photos, I see really nice backgrounds in their tanks. At first I thought it was the wallpaper (that you attach to the glass from the back of your tank). But then I realized the background looks too real to be merely a picture/wallpaper. I figured it has got to be some sort of a 3D background. Is it? If it is, where do you get it? Is it available in your local pet store? How do you "install" it in your tank? Does it take up a lot of space? Is it practical?