Loon - It's much cheaper to take your old rusty tanks and exchange them for NEWER Blue Rhino tanks and after you use up the propane then take them to your regular fill up area. In Florida you can buy a new empty tank at Sam's for about $40.00 and then you have to fill it up for about $14.00 giving you a total cost of about $54.00. You can exchange your old rusty beat up tank for a very nice looking Blue Rhino(pick out the best looking one in the cradle) for about $18.00 and it's at least 90% filled. That's a savings of about $36.00 in my book.