I was in a Home Depot today and saw this great looking artificial rock for walls. It is made of concrete and comes in a box, but piece by piece. So it is like individual rocks that fit together like a jigsaw puzzle. Kinda hard to explain, but very natural and in about 15 different styles and colors. Looks like it could be easily siliconed to the wall of a tank. So has anyone ever tried this stuff out and with what sucess? I would assume it would need a sealer on it but I plan on talking to the manufacturer tomorrow.