okay, I have a 30 gallon fish tank that I just moved into my dorm room. While turning it upright after cleaning it out, I appear to have broken a corner. glass has definitely been chipped off, but cracks appear to stop before the caulk/sealant stuff ends. I'm going to start filling it, so I guess I'll see. If it will, in fact, leak- what can I do to stop it up?