While attempting to drill holes in a 75 gallon tank (standard 48" x 18" x ~22"), I cracked the back pane. However, this was only after I successfully drilled a 1" x 11" slit in the right pane for an external overflow box. All other panes are in great condition. If anyone wants the tank, come and get it. You will have to either use it as a terrarium or replace the back panel. I'm located in North Oakland near Alcatraz and Telegraph. PM me if you want it.