Do you trust that you are getting a full tank when you exchange?  The video report below suggests that you could be getting less than you paid for, even though the tank they exchanged did appear to be within a pound of the weight of a full tank.  The point is, without weighing the tank, you really don’t know.  If you want to be sure to only pay for the actual propane you are using, you need to take the tank to a place like U-Haul and pay by weight.  Take a look at the video below and decide for yourself.  If you are more comfortable with refilling, wander on over to U-Haul and save some money…