This image shows how to build the sides up to make it easy to pour the Aragocrete™ mix into a thicker arch. Now you can cover the rock with gravel to finish the arch. We often use a different type of CaribSea gravel to cover our rocks, and this makes the finished arch look more interesting.

The bag will keep the shape together if the rock does break. We often break the bag rocks to fit them into the shape of the reef scape we are making. It is easy to make a bridge between two live rocks, so we can glue corals nearer the lights. The great thing about doing this type of rock in the ocean is that if the rock breaks it is soon connected by coralline algae. We have noticed how well coralline algae grows on plastic in our reefs.