I am setting up a 25G flatback hex, a 29G, and a 10G - all need backgrouns. I am not fond of what I have seen at fish stores, so I am wondering what to do. For the 10G, I probably will do what I have done before - use colored poster paper. It does not like water, but is cheap t replace and comes in a variety of solid colors. But the bigger tanks need something else. I am thinking of using soil-colored fabric for tem. Any other suggestions?