BB Bottom Guard???

[mark]

Got my rock direct on the glass. Took time to place so was stable, secured some together with zipties and figure if any does take a tumble, it's not like dropping through air.

[Beverly]

I also have my LR on the glass for about two years. Rearrange that tank often, and have had no problems with scratching or damage when rocks accidentally fall. I don't use cable ties or anything to keep my rock in place. I just make sure they are stacked solidly.

I considered putting cutting board on the bottom but was concerned that I couldn't seal it properly to prevent crud build up under the board.

[Der_Iron_Chef]

Ditto. I have rocks directly on my glass, not secured by anything. I came home yesterday, and things had taken a tumble. The glass was fine, and although I thought my open brain was done for...it's doing as good as ever tonight :-)