i did the same thing..........
here's what i did to fix it:
at Home Depot, they sell what is called "plastic corner guard"
here's a link:
http://www.homedepot.com/p/Trimaco-5-8- ... /202061350
it comes in different widths
with my tank, i ran a strip from top to bottom, and glued it on with a generous application of aquarium silicone sealer
be sure to use enough silicone so that there are no bubbles or air gaps in it
this must, of course, be done before any leakage occurs, and be sure the glass is very clean and dry before repairing
any excess silicone that squeezes out canbe cleaned away after the repair
worked very well for me!