should i worry about putting anything under the sand?

[kien]

I have a sheet of acrylic under each of my structures. If nothing else, it at least provides relief from those sharp rocks and preassure points on the glass. I'm sure the glass could take it but like you I'm paranoid like that

Actually, it was handy to have the sheets of acrylic underneath while I was in the process of aquascaping. This way I could slide the sheets around easily with rocks/bolders and all.