I vote thin later of sand. I'd also be scared about that rock tippin , is there any way you can secure it? Maybe putting a big of epoxy between rock and glass, idk just a thought .
Hmm maybe ill use eggcrate under the rixk
Just use epoxy to keep them together or zip ties. Easy fix
Ahhh, that is what i was trying to get at. So you basically have a few rocks epoxied together with a rod through them, then you cut the base to give a flatter, stable surface? Hard to tell from the photo, but looks great!
That's exactly what I did