I made this video last year so I'm bringing it back for the newbies to understand the process before we get hard water. Remember when filling, the 20 pound tank needs to be at room temperature and the one pound tank needs to be frozen and completely empty. Always weigh the one pound tank after filling to make sure you only put 16 oz of propane into it. This method is the method the designers of the refill coupling came up with and perfected. It works and you don't overfill the one pound tank like you can by using other methods people have come up with. You can refill and transport for personal use but not for commercial purposes. P.S. Self appointed safety police.....please move along to another thread.