Aquascaping ideas for a narrow tank

The most commonly used technique for creating depth to an aquarium is to slope the substrate lowest in front and higher in back. I personally like the idea of a black painted aquarium back with about 3" of substrate along the front, evenly sloping to about 6" to 7" in the rear of the tank. Heavily plant the tank to hide where the back of the substrate is. That's the only idea that seems to work that I know of. Hope this helps some.

You can create avenue's with your medium sized plants that go from the front to the back diagonally which create depth.

I have created an avenue with my Cryptocoryne lutea in my ten gallon tank here: http://www.picturetrail.com/gallery/view?p=999&gid=1497958&uid=835410 which maybe you can model off of. Anubias nana works well for this situation as well.

Credit: I found this information useful in the article The Art of Aquascaping by Karren Randall in the Aquarium USA 2002 Annual Magazine. You too shyould check it out, great stuff

2. Don't show the "join" where the substrate meets the rear glass. Where this hard-edged delimiting line would appear, in between clumps of plants for instance, let some rock or bogwood form a "horizon" that masks it. This is a trick I learned from the sublime dioramas of African and North American mammals in their natural settings at the American Museum of Natural History here in New York.

-from www.skepticalaquarist.com not otherwise known for aquascaping brilliance.