If anyone is curious (or just lazy like me and doesnt want to drive far for a refill), there's a home brew store in seabrook that fills CO2. It's food grade stuff, so a little more than what you could get at a welding store, but at $2 a lb I wasnt concerned. I don't know of other local places and used to go down to texas city to get my tank filled up. Never again!
http://www.brewersguild.net/
http://www.brewersguild.net/
