[Imperial]

A friend of mine just gave me his 40 gallaquarium. It's kinda an old shape aquarium (pre bowfront). The aquarium is kinda like a bowfront but with sharp edges likea half hexagon.

It looks kinda like this;
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/~~~~ \
|~~~~~|
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My question is, the aquarium is kinda old so I was thinking of re-sealing all the corners. I filled up he aquarium and left it full for a week and it did not leak. Should I re-seal it just in case and if so how should I do it. or should i leave it alone and not worry about sealing it.

Thanks