Co2 in Raleigh?

I am not too worried about the appearance of the tank itself really, it will be inside my aquarium stand so it will not been seen. I am more concerned however with the quality of the exchanged tanks, having had problems in the past with exchangeable propane tanks. I know from experience that sometimes when you exchange a new tank through a tank exchange program you are getting not only a much older tank but normally one of a lower quality and not to mention you have no clue how many times its been used or abused by previous users. At least with a new tank you can ensure that it has new seals, o-rings and valves. I would hate for it to start leaking or even explode once I get it home, these tanks are under a lot of PSI and can be very dangerous. With the before mentioned propane tank, the emergency pressure valve failed in the middle of grilling and all the propane came shooting out of the tank with it sitting right next to the grill, lucky for me it didn’t explode but it was scary, I’m attempting to avoid this.

I will probably go into Air Gas in person sometime this week and take with them some more about their exchange system, maybe they check each tank before sending them off to be filled. All though I do have to say that the person I spoke to on the phone was very helpful and he ended up telling me that they do not fill tanks on site they send them off to be filled so maybe the place that fills them tests them. I also need to get something clarified from them anyways, when I spoke with the person on the phone I believe he said that to lease a tank for a year was $105 + gas refills, if that’s the case it will probably be cheaper to just buy a tank and trade it in, because the tank is a onetime fee of $97 for a 5 pound tank. But the major bonus to the exchange program is I believe they will deliver a filled tank to my house whenever mine runs empty.

Still looking for more options and other people's input, I can Google all I want to but would still not get what I’m looking for, I am looking for input on a company that people have used in my area and their experience, that’s the reason why I started this thread not simply for someone to say “Google Welding Gas Supply”.

I sense more worry than needed. CO2 is a pretty harmless gas if the tank is good and some reasonable care is taken. Much less than propane we use so often. Have you run across the hydro testing and dating used? That is to assure that the tank is safe. Since there are literally thousands of guys using tanks for all kinds of construction where they really get abused and I have never heard of one blowing up, I have to assume the testing works. When thinking about tank exchanges, there is a good reason to check the date on the exchange tank, When you are dealing with welding shop folks, they just assume you will be using the gas quickly and getting it refilled in a couple weeks. That leaves them not too concerned about giving you a tank with a date that expires in a month or so. The guys who really use these tanks will have it back for refill before the hydro test expires. When I got my tank filled last time, I was asking about the charge for doing the hydro test and at that place they just take care of it for their customers and don't charge. Each business knows their tanks and just handle the testing when needed.
So what I wind up with is a tank that is safe but has lots of odd paint, markings and such but is really cheap and easy to refill without waiting or any of that hassle.