Just an fyi. Check your local suppliers before getting a 10lbs tank. Fills are never an issue, but when mine came up recertification, I could not find anyone actually willing to do the testing local. The best I got was an Airgas guy who definitely did not want my business ("you can bring it in and we'll ship it off to our testing center 100miles away and you *may* get it back if you're lucky").
Everyone and their brother would do an on-site swap for a 5 or 20lbs tank. The 10lbs just seemed to be an uncommon size around here and no one other than Airgas even said they might recertify it. No one I found did swaps.