The back pane of my 29 gallon glass tank shattered as I was drilling an outtake hole. I followed all recommendations by tutorial videos - diamond tipped drill bit, and water-filled ring of putty for lubrication/cooling. Maybe someone here can tell me what I did wrong so I don't waste another tank... Was it possibly tempered glass and not meant to be drilled? The glass shattered after I had already completed the hole and was wiping glass dust away with a rag. I will post some pictures, help!