55 gallon aquarium tank been sitting for 10 years who runs away from sitting?

hello, my people have a beautiful 55 gallon aquarium that has sat as 10 years in the attic that if I clean it still has not drain well in advance? Thanks PS still has gravel in it. Going to throw it.

Press on silicon with a finger nail. If it is still flexible, it's probably fine. If it is brittle and flakes, then you probably will escape. You can re-seal tank does. Always test any used tank. Just pull the patio or in the bathtub and loss of control that is 100% sure you can go ahead. If silicon is brittle and does not stick, not even bother trying to check it and scrape and seal again, then check.

10 Gallon Gold Fish Tank Aquarium