# Welding supply CO2



## inkslinger (Dec 28, 2003)

ggburke said:


> I was reading an article that said you should not use CO2 fro a welding supply company for fish that are sensitive to water born impurities? Is there truely a difference in CO2? Does this also include regulators and other equipment?


 There are different Grades in CO2 , But I use Fire Extinguisher fill Station to fill my 5lb CO2 for a couple of years with no problem. But the Paint Gun CO2 might have oil in it, I guess the best place to go is where they fill CO2 for Soda,Beer,and Medical Supply. The equipment would not matter in my IMO: 
A lot of people use Victors Regulator which is made for Welding.


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## Hoppy (Dec 24, 2005)

CO2 is stored as a liquid under pressure, and during the process of transferring it from one container, such as a delivery truck, to another container, such as a dealer's container, it gets extremely cold. Any water or mix of water and other stuff would freeze to ice during that process. Then, when the CO2 warmed up, that water would float on top of the CO2, but I believe the CO2 taken from the bottom of the dealer's tank, not the top. So, I doubt that you would get water soluble contaminants in any CO2 from any source. In any case I haven't heard of anyone having problems with contaminants in CO2, no matter what grade they use.


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## hale4david (Aug 6, 2008)

I've been wondering about this too after reading an article, same article possibly. I initially wasn't too worried about it since hadn't heard any similar problems while reading this site. The one thing that makes me wonder is that ever since I started injecting co2 my GH has jumped up like 5 degrees, my KH has also risen but to a lesser extent. Is it possible that the co2 I got from a welding supply shop is raising the hardness of my water? The only other variable that has changed since starting to inject co2 is that I also started to dose ferts. I'm dosing according to EI with ferts I got from Orlando. My hardness lowers after water changes so I'm sure it's not my tap water that has changed and I hadn't had a problem in the months prior to the two changes I mentioned. So what do you guys think, where is the increase coming from? Can Ferts or co2 change the hardness of your water? Or is more likely that I'm just missing something?


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## Left C (Nov 15, 2003)

Medical/Research grade CO2 is $$$$$ and very pure! 

I believe that welding grade and food/beverage grade CO2 are both 99.97% pure.

Also, the food/beverage CO2 is put in a special 50# cylinder that has a special lining.

This same food/beverage CO2 is also used for welding and filled into regular CO2 cylinders.


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## Left C (Nov 15, 2003)

hale4david said:


> ... Can Ferts or co2 change the hardness of your water? Or is more likely that I'm just missing something?


CO2 can break down any carbonates in your aquarium and increase the KH.


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## inkslinger (Dec 28, 2003)

I started out with an old Tetra CO2 Tank with regulator that you fill the CO2 Bells and the only way was getting an adopter to fill the tank or go to a Paint Ball Gun Shop which was the same size co2 tanks and the co2 left a film on the surface of my water and never use it since then.


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## PDX-PLT (Feb 14, 2007)

Welding CO2 and beverage CO2 are the same thing. My local home brew beermaking supply place tells customers to refill their dispensor tanks at the local welding place (Airgas).

Research / Medical grade is a different animal entirely.


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## KevinC (May 24, 2004)

Also remember that you are putting a gas-phase substance in your tank, so the impurities must also be in the gas phase. That makes it very unlikely any oil or rust or salts would get into your tank from the cylinder. The biggest impurities in the CO2 are probably nitrogen (N2), oxygen (O2), and water. Maybe some CO too, but not enough to worry about.


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## fshfanatic (Apr 20, 2006)

I dont buy gas sold at welding supply places as they tend to be the most expensive around here. For example, I get my 5lb canister filled for $5 at on of two liquor stores around here. The one welding supply place charges $16. No thanks.


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## BayBoy1205 (Jan 25, 2006)

Didn't know a liquor store would fill CO2. How did you find that out?


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## fshfanatic (Apr 20, 2006)

Called around. Not all of them sell CO2, but many do.


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## kid creole (Dec 25, 2008)

fshfanatic said:


> Called around. Not all of them sell CO2, but many do.


Ones that don't usually know who does.


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## CharlesEvans (Sep 24, 2009)

*Safe CO2*

I agree with what Left C said. It's absolutely safe for fish.


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## 2wheelsx2 (Jan 27, 2006)

Yep, been using welding supply CO2 for 4 years. No problems whatsoever.


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## hbosman (Oct 5, 2006)

inkslinger said:


> I started out with an old Tetra CO2 Tank with regulator that you fill the CO2 Bells and the only way was getting an adopter to fill the tank or go to a Paint Ball Gun Shop which was the same size co2 tanks and the co2 left a film on the surface of my water and never use it since then.



I get refills at a paintball shop, he also will fill standard tanks for kegurators to. In other words, same gas as anybody else uses with the exception of medical grade. The film on the water surface is quite common. It is proteins and can be dissipated with a slight increase in surface turbulence or a surface skimmer attachment.

I've heard that those little gas cartridges for bb guns would have oil in them but, I don't know that for a fact.


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