Sorry, I didn't mean to sound harsh, but that is one scenario that can't happen. Both the rock and the sand are softer than the glass, and either will give before the glass.

Oh SNAP! :lol:

Reminds me last year when I was installing a new light fixture for a bathroom. It was on a full wall mirror, and got the old one off, no problem, and the new one fitted on nicely. But then I was tightening (just one more little bit of a turn) up the rear back plate that was against the mirror through a drilled hole to the wall,...I heard this horrible snap, and a big crack ran out from under the back plate.

Had to pull off the whole mirror which was glued to the wall, piece by piece, and using a hammer to break more pieces to get it off.

That was not a good day....

How did sand get back there?

lol. This example more closely demonstrates flexion across an uneven stand. Which would break the glass, possibly.

If you wanted to put something down, the starboard product is often used. (cutting board material).

How about a light diffuser panel like this. It might actually look cool. Darn, why didn't I think of this a month and a half ago.

Hmmm, yeah, I like that. At the least it might keep my live rock from slipping around on the glass. Wonder if HD carries it. I am sure I have seen it somewhere. Thanks for the suggestion.

I'm still not sure how live rock is going to slip around on the glass...it's rock, it's just going to sit there. I ran BB tanks for years, and never had rock slipping around...