In "A New Hope," we learn that Luke and his aunt and uncle run a moisture farm. They never come out and say what exactly a moisture farm is, though. Presumably, since they live in the desert on a planet that's mostly desert, the farm equipment pulls moisture from the air to slowly create water. I always assumed that water was the crop — they harvested and then sold the water. But Luke also argues with his uncle about his obligations during the harvest season. Why would water have a harvest time? Wouldn't they just be pulling it out of the air continuously? So then I wonder if they use the water to grow crops, but we also don't see any crops at their homestead, besides some vegetables Aunt Beru cooks with. I just want some clarity about what goes on at the moisture farm.