The Saltwater Centerpiece design moved away from the back glass and took a chance with the only point of adhesion being to the bottom of the tank.

The two separate larger and smaller formations were built outside the aquarium, then secured in place with silicone.
DIY Aquarium Background
February temperatures in the workshop (garage) are offset with a 150w incandescent flood lamp. The radiant heat from the large lamp was welcome in an otherwise chilly work space.

The piece on the left was made with a combination of scraps from a previous project.
A blow torch was used to melt the polystyrene before applying cement to give it a more natural look of eroded stone.

The large tube sculpture on the right was crafted by my daughter.
Ample GE brand Silicon #1 is applied to the bottom of the formations to make sure they stay put.

This photo shows the bottom of the larger of the two formations.
The small black markings on the base were applied before the silicone, and then used to re-position the pieces permanently with silicone.

The goal of the careful positioning is to be able to navigate an algae scraper on all glass surfaces around the formations as needed once the aquarium is established.

Still early in the 30 day tap water rinse stage of this newly built design, you can actually see a film of calcium precipitate on the surface of the water. This servers as evidence of how important the rinsing stage is to prepare the aquarium for aquatic life.
Fast forward to three months later and the young marine aquarium is doing well. Too early to tell how the cement will hold up for the long term, but no signs of problems yet. A single Blue Damsel, and a newly introduced pink and yellow Diadema Pseudo are still debating boundaries.
welcome to
do-it-yourself aquarium and semi-aquatic background designs beyond the traditional
Dramatic AquaScapes