I wouldn't try lifting the tank alone with 120lbs. of sand in it, especially wet sand as it will be even heavier. A 55g tank has pretty thin glass and if it didn't break (which I think it would), the joints would be stressed. If it is on a stand that evenly supports the bottom of the tank and you and your helpers can lift the entire thing, then that might work. Other than that, definately keep the sand wet to keep anything in it alive and it should be fine.