The seals were old and failing, the actual leak though was accelerated by a chip in the glass. When I pulled the leaking seal it pulled a piece of glass out with it and you could see where the seal ahead of the chip had failed about halfway then the chip finished it off. Locals reported these tanks being from early to mid 90s in our local store and this one had touch ups but no evidence of a reseal. I am fairly reasonably confident in the assembly of the tank, more cautious about the lower and upper seals that attach the glass to the bottom of the tank and the top trim. Overall this tank is of poor quality from the get go. Lots of chips at the seams that had to of been there from day one as the original seal cover and fit the chips.