Can anyone recommend a good place to get CO2 tanks in the San Jose area? I'd rather not go through a LFS since they're going to be much more expensive than somewhere that caters to welders or beverage carbonation.
They're a hydroponics store. Of course it's still gonna cost you your soul, but yeah. I'd recommend just buying a tank off of Craigslist and then exchanging it at Airgas. At Airgas, they swap it regardless of the hydro date, so you can get one that is in current hydro.
Amazon has some that are nice and new for like $60 for a 5 lb tank, but if you do one of the exchange program type thing it isn't worth it to get a new one. Make sure you figure out where you will be going and see if they give you a different filled tank or not.