I am buying a used 55 gallon Oceanic aquarium with cabinet stand and
hood for $75.00. It's a deal I can't pass up. The last time I saw
the tank, it was full of fish and my friend took it down and put it in
his garage.

It's been sitting in the garage for at least 6 years, going through
winters below freezing and summers in the 90s. The tank has been
empty and just sitting there. Is there anything I should be
concerned
about?