I find it hard to believe that you have a hair dryer, Sam
Originally Posted by Avatar
It might work but there's no point in risking it, especially as it's easy to fix.
Just get a razor blade and cut through the silicone at right angles to the glass 6" on either side of the leak. Then align the blade flat against the glass and cut down and into the silicone where the glass meets from the bottom, do the same thing from the bottom cutting in toward the side of the tank and you can pull out the whole damaged section pretty much in one piece. Go back over it again with the blade to get as much of the old silicone off as possible. Then make sure it's dry (a few minutes with a hair dryer is usually all you need) and you're good to go. Can generally buy a tube of aquarium sealant at any hardware store but just about any clear silicone will do.
Do it right - literally an extra few minutes eliminates all the worry.