The shop by me told me one of my tanks was a year from being out of date. It cost more to re-certify it than to exchange it.
Exchange or refill is just a matter of convenience for me. A run to the shop takes more time and effort than a exchange. Propane shops are fewer and farther between anymore. You can get a exchange all over.
I take both the pair of 20 pounders off the trailer and a pair of Blue rino to be filled at the start of the season. After that if we need any we just exchange a Blue rino when we pick up the groceries for the next trip.
