 And if you've been doing propane tank exchange, of course you want to use up all the propane in the tank before you turn it in for a full one. Well at All 12 Zamzos we offer propane tank exchange, which is a quick and easy way to do it for sure. But what a lot of people don't know is we can actually refill your existing propane tanks as well. And it will save you about 10 bucks versus doing an exchange. But my favorite part about refilling your tank versus exchanging it is you don't have to wait until it's empty.