The above picture is of a fish tank I designed a rock wall for. Follow the below pictures to see the process I used to build the above set up with a natural rock wall background. The rock wall was built in 2012 and as of July 2020, the wall is still holding in place.
Choose rocks that follow the shape of the container. If you are using a standard aquarium try to find thinner flat rocks for the top and slightly larger rocks for the bottom.
Clean all the rocks to remove any debris. Some people recommend boiling the rocks if you are planning on using them with pets to kill any potential parasites. Never bake them though. If I’m planning on using the rocks for underwater I collect them on dry land. My theory is any parasites that would live underwater wouldn’t be found on dry land. I don’t have evidence to support this theory; however I’ve never had issues with parasites when doing this.
Once you have the rocks you will be using, lay them out as a background and basically fit them in like a puzzle. Move them around until you get the desired look you are trying for. Try to put the smaller rocks up top and the larger rocks on the bottom.
When you are happy with how your background looks it’s time to silicone the rocks on (If it is not glass you should research the best adhesive to use). I’ve used GE Silicone 1 which although on the bottle states not to use for aquariums, I have read from multiple sources it is safe for aquariums. When using Silicone, it is best to work outside or a very well ventilated area.
Allow the rocks to sit for 24 hours before trying to stand the container up. Once the 24 hours have passed, carefully and slowly stand the container up. If possible get help with this so you can have free hands ready just in case you need to catch any rocks.
After all the rocks have been attached, it’s time to fill the spaces in so you can’t see the glass in the back. You can use smaller stones or sand to fill in the gaps. Coat the back glass with silicone and push the sand or smaller stones onto it.
Add in any other decorations, such as wood, to make the set up more interesting.
After the silicone has completely cured, and you no longer smell it in the set up you are ready to add you substrate, plants, and whatever else you would like.
Enjoy the cool rock wall you custom designed and brag about it to everyone you see…well maybe not the last part.