I don't have any experience building tanks.
But I do know that the silicone that you see on the inside of the tank that rounds out the interior corners plays no part in structural integrity. Only the silicone that is inside the joint or actually between the panes of glass provide strength.
When you get a leak, it means that a small section of that structural glue has given out. To me this suggests the beginning of a larger potential failure to come... Maybe this isn't always the case but I certainly wouldn't take that chance.
When you plug the leak by adding silicone to the inside of the tank, you do not fix the larger potential issue of structural integrity, you only stop the water from coming out.
Like I said, I'm no tank building pro but I would not use a tank that has leaked unless it had been completely re-glued, not just re-sealed.