Things You'll Need
- Empty fresh water aquarium
- Tape measure
- 2-inch thick sheet of extruded polystyrene foam
- Sharp knife
- Tube of 100 percent, non-toxic silicone sealer
- Heat gun
- Plastic tray
- Small trowel
- Cement
- Concrete acrylic fortifier
- Paint brush
- Gloves
- Concrete paint (optional)
- Paint brush (optional)
Instructions
Measure the back glass pane of the aquarium and use these measurements to cut the extruded polystyrene foam sheet to fit the rear of the tank.
Cut this piece of the polystyrene foam in half, from top to bottom, as you will not be able to fit the full sheet into an aquarium which has glass support braces connecting the front glass pane to the rear glass pane.
Use the sharp knife to cut out six to eight small rock-shaped pieces of polystyrene foam from the remaining sheet.
Squeeze a teaspoon full of non-toxic silicone sealer on the back of the small pieces and glue them to the two polystyrene foam panels. Put the two panels aside and leave them to cure for 24 hours.
Cut rock shapes of various sizes into the two polystyrene foam panels.
Use the heat gun to smooth and round off the rock shapes that you have carved into the two panels, as well as the rock shapes that you have glued on the two panels of polystyrene foam.
Mix the instant cement as per the directions, in a plastic tray and add the acrylic fortifier. Add water slowly to this mixture, until it is runny enough to pour off the trowel.
Apply the runny cement mix to the front of the two polystyrene foam panels. Place them aside and leave this first layer of cement to cure for 24 hours.
Mix a second batch of cement, but include an extra small amount of cement to this batch, before adding the acrylic fortifier. This mix must not be runny.
Put on your gloves and smear the mixture over the front surface of the two polystyrene foam panels. Place the panels on one side and leave them to cure Leave for 48 hours.
Paint the front section of the two panels with aquarium safe pain, if you so choose. Leave the paint to dry for at least 24 hours.
Apply a thick layer of non-toxic silicone sealer to the entire back of both polystyrene foam panels. Place these panels against the inside back pane of the empty aquarium and press them gently against the glass. Leave the silicone to cure for 24 hours before adding water to the tank.
Fill the aquarium with tap water and leave it for an extra 24 hours. Drain this water and fill the aquarium in preparation to add your fish.