I brew and bought my tank at a local welding shop. They exchange, just like propane and you don't have to worry about the cert. ~27 bucks last time. Can return the tank for a 'core' charge.
Dang it, I knew there was one on montopolis, couldn't remember the name. I'm fine with refilling. Should be about $10 - $15 per fill from here out. I typically only need 1 or 2 fills per year.
