Your Powertank is delivered empty, so you'll need to find a filling station. Some welding supply stores can fill your Powertank on site, but many only offer a cylinder exchange service. No good. Try a fire extinguisher business instead. We went to Certified Fire Extinguisher Service in Whittier, California. Steve advised shopping around, as refill prices can radically vary from place to place. Certified's price was excellent and the service was fast. If you go to Certified Fire Extinguisher Service you'd better bring green cash or your checkbook because they don't take credit or debit cards.