I am a new member. With much help from the members here I finally got my 70gal (bought used) set up and cycling the water. All of the sudden yesterday I heard a noise and walked into the room to find the front glass had cracked top to bottom and water was streaming out. After frantically bailing water and soaking uo water with towels we got it emptied in probably 3 minutes flat. I bought a new tank and set it up and filled it with water late last night to start the process all of again. Now I am concerned that I might have done something wrong before and I don't want to repeat that same mistake. Could I have done something wrong? I checked and leveled the stand, tank, tank1/3 full, tank 2/3 ful and tank 100% full. It was level, plumb and square.