I've been trying to figure out what to do with my old tank(Biocube 14) and I decided I wanna drill it and make a small sump for it. I ripped out all the plastic/acrylic that forms the 3 filtration chambers in the back so as to increase the usable display tank size. I figure I'll buy one of those small 5 or 10 gallon tanks(whatever fits in the stand) and that way I'll have room for a better skimmer & a refugium.

Couple of questions, the back wall of a Biocube 14, is it glass or acrylic? If glass, is it tempered?