Cool, thanks. I'll look into MO Malt. I did find 3 other places that fill them. Weber Fire & Safety will fill a 20# tank for $30 and a 5# tank for $18 which to me is high (I used to pay $14 to get my 20# tank filled and $10 for my 5#). Cee Kay has said that they will fill as opposed to swap but it takes 2 days to get your tank back. No price from them yet. I also found another place in Fenton called St. Louis Recharge that specifically mention filling CO2 tanks for homebrewing on their website. They are located off of 141 near 44. I haven't gotten a chance to call them yet. I checked with Design2Brew and they said that currently, they only swap them, but I can request that I get the same tank back from their filler, but they make no guarantees. They are looking into being able to offer that, but don't currently.