Aquascaping with sand...?

[Heady]

I am setting up a 100 gallon tank with onyx sand and would like to have a raised plateau area in the back corner of the tank for an interesting bit of variety. Does anyone know how to keep the sand from evening out with the rest of the substrate? I.e. rocks etc?

 

[Matak]

I terrascaped using rocks 2" wide, 1" tall and the length of the tank from front to back. I epoxied these rocks together so that they are about 4" tall. I placed them at the bottom of the tank before adding the substrate to be sure they were anchored enough not to move. They make a 2" high separtation between the left side and the right side of my tank. If you want to cut rock cleanly, you will need to get a saw with a diamond or carborundum blade. An angle grinder will also work, but it will take more time.

 

[Two Tanker]

I use a piece of plexi glass to hold the gravel/sand back in my tank, and then stack some rocks across the front of the glass to make it look natural.

 

[OrionGirl]

I highly recommend glueing the rocks together, or using the plexiglass. When I originally setup my 40, I wanted three levels--one about 6 inches deep, another about 4 inches, then the main level to be about 3 inches. I just stuck the rocks into the gravel to make a wall, and added gravel behind the walls. 3 years later, I took the middle shelf down completely, and the high shelf is now a wall--the whole tank is the same depth. Sigh. Just another reason I need to setup another tank and rebuild this one!

 

[somefinnfishy]

I'm going to use a large piece of drift wood cut and hack it to size hollow it out a bit and silicone into place.