How long is too long for a tank to sit empty?

[jm1212]

it should be fine...worst comes to worst you have to reseal it.

 

[lymabean]

i have a 20 gal that i want to set up soon. its sitting in my attic, its not in sunlight, but its not very temperature regulated up there. its been out for about 2 months. think thered be any trouble?