Create a stable rock wall, using live rock, dead rock, or a combination, by placing a framework of PVC piping under the substrate and then placing substrate (sand or gravel) around the PVC, but have the rock wall rest on the PVC so that tunneling pet fish can still tunnel without undermining the rock wall support. Be careful not to use PVC glue. Use aquarium sealant or other glues designed specifically for fish tanks. Another option is using a hammer to drive the PVC piping, PVC “T’s,” and other connectors together. Or assemble the PVC piping and connectors, then drill through them both and apply plastic strips as though you would a plastic nail to lock the connectors and pipe together. Do not use metals, such as wire or screws, as they are very toxic to your aquarium fish. Distribute the rock wall weight as evenly as possible along the length of your fish tank.
Assemble, hammer, and/or drill the PVC support structure outside of the fish tank, then reassemble it inside the tank after all the drilling, cutting, and sizing are completed. You can disassemble a large rock wall support system into two or smaller pieces that fit into your tank more easily. Do not drill the PVC while it is underwater (sorry, couldn’t resist).
Position the rock wall away from the sides of the fish tank so that you have sufficient room to clean off the algae that will eventually grow there. Leave sufficient space to permit vacuuming up the debris that accumulates on the bottom. TIP: Experts aim for some water circulation to push debris into specific fish tank locations designed to be easy to access for maintenance.
Depending upon the size of your aquarium and the needs of your pet fish species, you could set up your rock wall into various shapes that balance out your aquascape visually while considering weight distribution. Arranging your live rock wall into a “W” when viewed from above would be ideal, but it would require more space than if you set up your rock wall into a “V” when viewed from above. If you have sufficient space and have more free-swimming pet fish than tunneling fish or cave-dwelling fish, you could set up your rock wall into two “L’s” (when viewed from above), one on the left side and one on the right side of your aquarium, leaving free space in between. This is an ideal way to “bracket” your aquascape and accentuate the aquarium environment. If you have a 90-gallon fish tank or larger, you may be able to incorporate a combination of two or more of these shapes. For instance, “L’s” on both sides, with a “V” or a “W” in the middle.
Be sure to leave holes extending from front to back throughout your rock wall, especially if you will be using live rock or live corals, to eliminate any dead spots in water circulation. These aquarium inhabitants depend on water circulation to provide food and sweep away waste.
Before you start designing your aquarium, you should think about where the fish species you want to keep as pets normally live. With these tips, you can take care of both saltwater and freshwater fish tanks, no matter how big or small they are (20 or 200 gallons).
