# how long does your 20# CO2 tank last?



## mcubed45 (Jun 30, 2010)

pleasantly surprised that my 20# tank lasted just a couple days shy of 7 months.

the tank supplies a 75g, 30g, and 20g. all 3 have been running standard ceramic diffusers with drop checkers reading light green for 8hrs a day. 

the CO2 tank also supplies my home-made kegerator. i've gone through about 2+3/4 kegs (5gal) since i finished building it a few months ago. Micromatic says a 20# tank should last for 60-80 5gal kegs (depending on serving pressures, etc) so i don't think the beer used up all that much of the co2. 

how long do your tanks usually last? from what i've read, i think i've gotten a pretty reasonable run.

also this is with over 130 feet of SILICONE tubing running to the various aquariums. how strange that the co2 tubing retailers repeatedly tell me it's worth paying 10x as much for co2 tubing b/c of the cost of the co2 i'd be losing with silicone. :icon_roll


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## audioaficionado (Apr 19, 2011)

Anything >6 months is excellent IMO. I'm only feeding one medium tank 24/7 and I'll be thrilled if I make it past 6 months on my first 20# filling.


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## kevmo911 (Sep 24, 2010)

That sounds about right for a 20#. I have a 5# running a 30g, and last refill lasted maybe 5 months.


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## Jeffww (Aug 6, 2010)

On my 60P....well let's say I'll probably take the tank down before I replace it..


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## herns (May 6, 2008)

mcubed45 said:


> how long do your tanks usually last? from what i've read, i think i've gotten a pretty reasonable run.:icon_roll


Your 20# runs 3 tanks, so that's about right.

I have 20# that runs 20G. Its been a year since July 27, 2010 and still has 700psi left. I have 5-6 bps, 8 hrs/day.


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## wkndracer (Mar 14, 2009)

Had the time and the thread made me look LOL
feeding two 75g tanks via controllers 24/7 and using down flow reactors 

20lb cylinder swapped, 1.2lbs @ 250psi 5-21-10 to 4-1-2011
I started running power heads with air bleeds spitting some air and adding surface agitation. 

20lb cylinder swap @ 500lbs. Remaining (red zone on HP gauge) Cylinder 3lbs. From empty. 12-30-08 to 5-21-10 = 16m21d


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## HypnoticAquatic (Feb 17, 2010)

im getting about 10-12 months on my 20lb just running on my 40b on i think 10hrs a day id have to double check though, got a few days left before its done. for running 3 tanks on a 20lb thats pretty dam good for 7 months but it does show how its just a estimate due to many variables involved.


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## Bettatail (Feb 12, 2009)

mcubed45 said:


> also this is with over 130 feet of SILICONE tubing running to the various aquariums. how strange that the co2 tubing retailers repeatedly tell me it's worth paying 10x as much for co2 tubing b/c of the cost of the co2 i'd be losing with silicone. :icon_roll


 there is an interesting article about the characteristics of the silicone tubing, please check it out.
http://www.dowcorning.com/content/publishedlit/52-1067-01.pdf
The PDMS in table one is silicone tubing.


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## NWA-Planted (Aug 27, 2011)

Is there a chart which gives estimates for how a tank should last? I had a 5# feeding my 55 gallon tank and I want to say it only lasted about a month....


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## VeeSe (Apr 16, 2011)

NWA-Planted said:


> Is there a chart which gives estimates for how a tank should last? I had a 5# feeding my 55 gallon tank and I want to say it only lasted about a month....


Hate to say it, but you likely have a leak in your setup if you aren't running an incredibly high bubble rate.

There's no chart because it's so different from case to case that you really can't say. For example, how long a tank lasts depends on how much CO2 you are using daily. This depends on whether or not you run CO2 24/7, 8 hours a day, 10 hours a day, etc. Then, it also depends on how high your bubble count is. If you run 5bps, you will use up your tank faster than if you run 2.5bps. Then, it also depends on your working pressure. The amount of CO2 in one bubble at 30 or 40 psi could be more than the amount of CO2 in 3 bubbles at 15psi, so 1bps at 40psi is like 3bps at 15psi. Then, it also depends on how big your bubbles are. This depends on your bubble counter, the angle of the BC, and other things. 

Do you see why there's no chart? =)

That being said, your 5lb tank should last you way more than 1 month unless you are running CO2 24/7 and using higher than 4bps at a reasonable working pressure. My setup had huge leaks awhile ago and it still lasted half of a month at 3-4bps and high working pressure, so I suspect there is a leak somewhere in your system.


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## NWA-Planted (Aug 27, 2011)

I think the operating pressure on my regulator is roughly around 50 pounds. Hmm yes most definitely sounds like I have a leak! Guess with the new tank a revamp on the CO2 system is defintely in order. Might as well upgrade to a solonoid style, thank yoU!


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## talontsiawd (Oct 19, 2008)

7 months sounds about right, considering how many tanks it's going to. Mine lasts about 1.5 years but that is on a single 29 gallon.


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## DanCottle (Apr 12, 2011)

My 20oz PB tank lasts 4 months on my 40breeder lol


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## jkan0228 (Feb 6, 2011)

DanCottle said:


> My 20oz PB tank lasts 4 months on my 40breeder lol


Not sure if you think 20# means 20oz but it means 20lb.... 20oz with 4 months on 40b is not bad...


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## herns (May 6, 2008)

An update to my post (on #5). I'm expecting a refill few months from now. The pressure now is getting low to 500psi. My last refill was July 27, 2010.


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## DanCottle (Apr 12, 2011)

jkan0228 said:


> Not sure if you think 20# means 20oz but it means 20lb.... 20oz with 4 months on 40b is not bad...


Haha i know what a pound symbol is. I was surprised it lasted that long.


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## majstor76 (Jun 11, 2010)

mcubed45 said:


> pleasantly surprised that my 20# tank lasted just a couple days shy of 7 months.


I had 6 months run of 10kg(20lb) tank on 100g aq (24/7). Now i got EM and after 8 months pressure is still very high. I dose co2 12h a day


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