# 2.5 lb CO2 tank?



## Talonstorm (Feb 16, 2005)

Hi. I have been wanting to add CO2 to my 29 gallon tank for quite a while. The price on some of this equipment is very high, but I found a used (refurbished) 2.5 lb CO2 tank, says "can be used for beer or paintball". Would this tank be suitable for use on my aquarium (too big, too small, not the correct adaptors, etc.)? Of course, I realize I need a CO2 regulator, pH meter, and diffuser also, but I am trying to save where I can. Any help would be great. I just want to be sure I don't buy something I can't use.

Thanks,
Tina

PS - I thought about going DIY with the yeast bottle method, but decided I didn't want the mess and since I would probably eventually upgrade anyway, I might as well try to start out right.


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## Roy Deki (Apr 7, 2004)

I purchased (leased) my 2 co2 tanks from a gas and welding supply store. I have a 10g and a 5g, they cost about $45.00 full. When they are empty, I then take them back and trade them in for full one for $14.00

Also the bigger the better providing you have the space under the tank. It will last longer.

Hope this helps


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## Porkchop (Mar 1, 2005)

I just bought a 10lb cylinder. I was going to buy a 5lb, but then I found out the refill between the two sizes is only $2 different ($11 for 5lb and $13 for 10lb). The 5lb cylinder is $80 filled, and 10lb cylinder is $120 filled. In a long run, you will save more with a bigger cylinder.


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## david lim (Mar 30, 2004)

Talonstorm said:


> Hi. I have been wanting to add CO2 to my 29 gallon tank for quite a while. The price on some of this equipment is very high, but I found a used (refurbished) 2.5 lb CO2 tank, says "can be used for beer or paintball". Would this tank be suitable for use on my aquarium (too big, too small, not the correct adaptors, etc.)? Of course, I realize I need a CO2 regulator, pH meter, and diffuser also, but I am trying to save where I can. Any help would be great. I just want to be sure I don't buy something I can't use.
> 
> Thanks,
> Tina
> ...


It should have the correct valve (CGA320?) for a co2 regulator to connect. I had a 3 lb co2 bottle for a little bit, but it was a modified O2 tank with a refit CGA320 (is that the right one?) valve.

For experience I would say try to DIY but you'll enjoy the injected more with less headache .

For saving money you don't need a pH meter, although it's handy to have one to get accurate pH readings. I also noticed that you don't have a flow control device (ie. needle valve) on your list. I didn't know if this was included with your regulator but definately invest in a needle valve. It will allow for more accurate control of your CO2 output and also reduce the CO2 tank dumping effect.


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## Talonstorm (Feb 16, 2005)

Thanks for all the help. I decided not to go with the 2.5 lb tank. I am going to make a stop at the welding shop around the corner from my house and see what they have there.

Thanks again,
Tina


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## Scipionyx (Apr 5, 2005)

Get the 5 lb, and always remember to ask for beverage or medical grade CO2, due to the fact that it has been filtered and processed to remove impurities that could leach into your tank. Welding grade is not filtered in any way .......


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## Laith (Sep 4, 2004)

Scipionyx said:


> Get the 5 lb, and always remember to ask for beverage or medical grade CO2, due to the fact that it has been filtered and processed to remove impurities that could leach into your tank. Welding grade is not filtered in any way .......


As far as I know, what they call the "technical" (as opposed to medical) grade CO2 here is 99.5% pure CO2. What else could be in there that could harm fish/plants? I had heard that any "impurities" in the remaining 0.5% would mostly be O2...

Anyone have more info on this?


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## zeek (Jan 5, 2005)

Odd that the prices vary so much!
I got my 20# bottle from a welding supply place for about $110USD, and refills are only $10USD. A 20# lasts well over a year on my 120gal.


I've never heard of the potential impurities in welding-grade CO2. I imagine medical-grade costs quite a bit more and is more difficult to obtain depending on location, meaning proximity to a hospital or care facility.


Isaac


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