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Refilling CO2 Cylinders

3K views 11 replies 7 participants last post by  PaulH2 
#1 ·
I asked a separate question in the New Mexico group (but it seems to be pretty sparsely populated) so I'll ask a more generic question here if that's OK.

I had a Dennerle pressurised CO2 system in a 55gal tank, 20 odd years ago when I lived in the UK, and am just getting back into planted tanks now. Previously, I used to get the CO2 cylinder (a 5lb I think) refilled at the local fire extinguisher store.

I'm setting up a new system in a 45gal tank, also with a 5lb cylinder, and am trying to figure out where to get it filled. Hopefully, someone has already figured this out in the Albuquerque area, but just in case, I wanted to ask a couple of more generic questions:


  1. What type of store / facility do you get your CO2 cylinders refilled at?
  2. Do you insist on food grade CO2, or is a lower grade (e.g. welding / fire extinguisher / paintball gun) acceptable?

I'm guessing what I used to use, being for fire extinguishers, wasn't food grade, and I never had any problems (from what I've read, the principle difference is that lower grade CO2 has larger amounts of other gasses, mostly nitrogen and oxygen), so I'm assuming the issue is principally that you get a little less CO2 for the money, which wouldn't be a big deal, or are there other potential problems (e.g. small amounts of toxic gasses, or other contaminants that might damage / degrade regulators, diffusers etc)?

Thanks very much,

Paul
 
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#3 ·
No reason to use "food grade". Industrial is just fine. Is there really even a difference other than price? Anyways...cheapest will be going to a welding shop or industrial gas supplier. Paintball shops/fields are also not a bad place if you have any in your area. Unless you want a new bottle for appearance, either buy the cheapest bottle you can even if it's all beat up and just exchange it at the store. Two reasons why I do it this way....1. You don't have to wait. Sometimes the shop can't fill your tank as soon as you walk in. They may keep your tank for a few days until they can get to it. Not sure that's a common issue but it's happened to me. 2. and biggest reason, hydro-testing. If you have your own tank and insist on it being refilled, you have to maintain the hydro-test which means you pay for that and it is common for the shop to keep your tank for a period of time because they generally only batch test. So depending on when you drop the tank off to be tested, if they have few tanks needing tested...you wait until they have enough. You could also get lucky and they are at the number they need and your tank gets tested within a day or two. I had to wait nearly 2 weeks once before I decided to just start doing trade-ins instead of keeping my tank. By trading, you always have a tank within date and even if it goes out of date while you have it, when you trade it in, they take it and just give you a good in date tank at no addition cost to you. Granted that's only something you have to worry about every 5 years, but it's still a consideration and not likely you'll buy a new tank that has the full 5 years left on the tank so at some point you'll likely need to have it tested.
 
#4 ·
If you don't care about getting the same tank just go to Airgas and swap it out. It's considerably cheaper this way. For example, to fill up a 5lb tank at the local brew place it's $18. If I take my old 20lb to airgas for a swap it's $32.

The cool thing about Airgas too is that you can bring in an ancient tank with an expired hydro date and they will still swap it out. A lot of the brew places will not fill up an expired tank.
 
#5 ·
Lookup welding gas on Google maps. You will find tons of suppliers in your area. Roberts, Airgas, Arc 2 etc etc. Call them, explain your situation, do not go for beverage quality. Just ask for regular, welding grade CO2.


They will either swap your cylinder or fill it...usually it is their preference.


My just got my 10 lb tank filled for $26.35 out the door.
 
#12 ·
Thanks everyone for your advice. It looks like I'm going with Airgas, everywhere else I called wasn't interested in small stuff, only bulk, and they make ordering pretty easy (compared to some). Sticking with a 5lb tank for now as I don't have much space.

Paul
 
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