how do i know when it is time to reseal an aquarium? i bought a tank that has been used for 10+ years(built in 94)made by all glass,but it has been empty the past few months..well anyways i filled it with water and let it sit for about 5-6 hours then decided to move it so i emptied it and started to worry about if it might need a reseal or not.i need to get some shims tomorrow to put under the stand to make sure it is level so it is empty but any opinions on whether or not a reseal is needed?