Once the faux rock has cured over night, it will be easy to apply some texture effects. Small amounts of Pond Shield can be used to dab various spots on the faux rock to create depth. Use darker colors in more recessed areas and lighter colors on edges.
Do not be afraid to over lap colors and allow one color to bleed through another. This will make the end result look more realistic.
The colors chosen for this particular faux rock piece are meant to compliment the color of the plants that will be placed inside the aquarium around the rock. We used blues and greens as highlight colors to accomplish this.
Once the faux rock has been completed and has cured for at least 24 hours, it can then be glued in place. Be cognizant that the faux rock is made of foam and the foam is going to want to float. A good, non-toxic adhesive will be needed to keep the faux rock from detaching from the glass after the water is added to the aquarium. be sure to allow the adhesive to cure completely according to the instructions included with the adhesive you purchase.
Add gravel around the faux rock and slowly add water. Once the water is close to the top, plants and such can be added.