# CO2 vs. Air Line Tubing?



## Teebo (Jul 15, 2015)

Is there any difference? I thought I had read somewhere at one point that CO2 will escape through standard air line tubing? I like the black airline I see for sale at my LFS.


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## scapegoat (Jun 3, 2010)

Teebo said:


> Is there any difference? I thought I had read somewhere at one point that CO2 will escape through standard air line tubing? I like the black airline I see for sale at my LFS.


looks like typical tubing will leak co2 through the wall of the tube.


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## Teebo (Jul 15, 2015)

scapegoat said:


> looks like typical tubing will leak co2 through the wall of the tube.


I was afraid of that. Is there a grade you search for tubing by? Or just "CO2 Tubing"


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## scapegoat (Jun 3, 2010)

not sure. I purchased mine a long time ago.


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## PlantedRich (Jul 21, 2010)

This is a frequent flyer question and normally has two sides. One yes, one no. I'm on the no side! 
In ordering parts/supplies from USPlastics, I was asked about what type fittings I wanted and was referred to their tech section for advise. they took the question very seriously and wanted lots of info like what chemical I was planning, what pressure and distance and probably more until they found it was CO2 at under 100PSI. At that point they told me anything they sold would work as CO2 is very light duty and at that pressure there was no difference in what I used. I had also heard/read that there was leakage in some tubing, so asked about that. The tech guy said that it was true that some molecules of CO2 would leak out the the walls of some tubing but that was under higher pressure and temperature, etc. 
His answer was that CO2 would go out the end of the tubing so much easier than the sidewalls that it was a non-factor. 
His point was that there was no reason for a molecule to force it's way through between the molecules of the wall when the end at the diffuser was almost an open pipe? 
I take the answer from tech support who could have sold me most anything but told me to just use whatever I had. 
with time using the stuff, I am now certain that I lose a whole lot more by leaving leaks than I will ever lose through the sidewall. Invest in better fittings that don't leak and don't sweat the small theoretical stuff.


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## houseofcards (Mar 21, 2009)

You could use any tubing. For the distance it's traveling there really isn't any difference. The silicone tubing is easier to attach to diffusers since it's soft, but you could use a match/lighter for a few seconds on the end of the harder type tubing to attach if it doesn't stay on or pops off easily.


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## Teebo (Jul 15, 2015)

Thank you


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## jeffkrol (Jun 5, 2013)

Tubing Selection Guide from Cole-Parmer

I prefer anything but Silicone tubing.. 
co2 tubing ? - Aquarium Plants - Barr Report

Just to be on the safe side w/ pressurized CO2 (40psi outlet pressure)
SEE #18...........


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## houseofcards (Mar 21, 2009)

Been doing it for 10 years with the crappiest tubing imaginable. 

Yes you might lose some co2 gas over what an average of a 3-5 feet. Let's see if I do my calculations correctly that's $0.010 per cylinder fill. :crying:

Like so many other things in this hobby, there are those who want to over analysis this as well.


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## Teebo (Jul 15, 2015)

Better be safe than sorry, I overbuild everything. What is the standard aquarium ID...1/4" ?

I may buy FEP tubing, I would not have to fuss with replacing it over time. I would be under low pressure as I have no air stone, or diffuser. It pumps directly into my cerges reactor at a much lower pressure.


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## The Big Buddha (Jul 30, 2012)

Twice I had silicone tubing fail on me, it also seems to stretch a bit at 30psi. It was evilbay tubing labelled co2 tubing....
I have since switched to polyurethane tubing with quick connect fittings, so far very happy with the switch.
Picked it up off amazon.

.


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## PlantedRich (Jul 21, 2010)

The main points for me are the pretty simple ones that don't really take a lot of study. We need to find tubing that works well with the fittings we use. That's a matter of getting hands on with both as there are tiny differences in sizing and how the tubing reacts to pressure and temperature. Some works well with barb fittings, others not at all, so we need to get a good match there. 
For leaking through the walls, I find that is another of those big boogie man theories that are promoted and flourish due to the internet. 
If you run 100PSI at 100 degrees and 200 feet, tubing may leak but doing what we do at the pressure, temperature, and distance we run, the CO2 can go out the end much easier than force it's way out the side. 
Don't let statistics get in the way of real life!


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## houseofcards (Mar 21, 2009)

The Big Buddha said:


> Twice I had silicone tubing fail on me, it also seems to stretch a bit at 30psi. It was evilbay tubing labelled co2 tubing...
> .


Never had a problem with silicone tubing. How did it exactly fail? BTW the stuff sold on eebay is the same stuff sold on Amazon and countless other sites/stores, etc. I'm not sure why it's evilbay, when sellers there live and die by their feedback. Most go way beyond what other sellers might do to make buyers happy.


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## The Big Buddha (Jul 30, 2012)

Small splits length wise in the tubing. Tubing was pretty stretched too, compared to the extra tubing I hadn't used.

.


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## jeffkrol (Jun 5, 2013)

"real world" or not, I see no point in using silicone tubing when lower permeability materiel can be found at about the same cost more or less..
Esp. w/ high pressure injection.. PVC or polypropylene, or polyurethane are orders of magnitude less permeable..

http://www.processsystems.saint-gob...ts/Peri_Pump/PS-PeriPumps-Permeability(1).pdf
http://naldc.nal.usda.gov/naldc/download.xhtml?id=6871&content=PDF

Note Versilik spx-50 in both resources......

some say why, I say why not (not use it..)

That said and playing around. Tygon 4040-a @ $1.15/ft.. is.. err .. yellow... and low permeability..

http://www.processsystems.saint-gob...Documents/Flexible_Tubing/FT-Tygon-F4040A.pdf

and can take 50psi w/ 1/8id tubing.. 

https://www.walmart.com/ip/STENS-115-343-TYGON-FUEL-LINE/178878853


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## jrill (Nov 20, 2013)

The loss is so insignificant that imo it's not worth discussing. Use what's cheapest or what you have.

Sent from my XT1585 using Tapatalk


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## jeffkrol (Jun 5, 2013)

Everything is worth discussing.. 
$12.50/100ft.. not silicone.. 
working pressure 40psi...

Flexible Vinyl PVC 1 8 x 1 4 Tubing 100 Ft from Cole-Parmer

6.8 vs 20,000


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## houseofcards (Mar 21, 2009)

jeffkrol said:


> $12.50/100ft.. not silicone..
> working pressure 40psi...


You forgot the $10.00 (cheapest freight) they charge to ship it. Airline tubing :surprise:

In fact, since your losing so much costly co2, I would opt for the $50 overnight freight...................


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## jeffkrol (Jun 5, 2013)

houseofcards said:


> You forgot the $10.00 (cheapest freight) they charge to ship it. Airline tubing :surprise:
> 
> In fact, since your losing so much costly co2, I would opt for the $50 overnight freight...................


your conveniently leaving out the price of silicone tubing.. 
(hint: close to $1/ft)
PVC tubing is available anywhere..
Sioux Chief 1/4 in. O.D. x 0.170 in. I.D. x 10 ft. Clear PVC Tubing-900-01030C00101 - The Home Depot

no Home Depot by you?
27 cents/foot plus TAX..  and less CO2 "waste".. 

Cheap and not "as-porous" is not mutually exclusive..


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## houseofcards (Mar 21, 2009)

jeffkrol said:


> your conveniently leaving out the price of silicone tubing..
> 
> PVC tubing is available anywhere..
> Sioux Chief 1/4 in. O.D. x 0.170 in. I.D. x 10 ft. Clear PVC Tubing-900-01030C00101 - The Home Depot
> ...


I'm nor leaving anything out on purpose. My response is tongue-in-check. It's just a conversation about nothing, about numbers that add up to virtually nothing. It just adds another complexity to a newbie trying to get into planted tanks that is completely not necessary to worry about.


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## sohankpatel (Jul 10, 2015)

Silicone tubing hardens up for me when I use it for co2, it gets brittle and stiff.


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## burr740 (Feb 19, 2014)

Silicone tubing is not $1/ft. I've been using this stuff for a couple of years - Hagen Elite Elite Silicone Airline Tubing Aquarium & Pond Airline Tubing . Similar priced at any pet store.

Having said that, after a year or so I do notice it getting brittle around connections, anywhere the tubing is stretched or in a bind. 

I'm in the process of switching all my tanks over to CO2 tubing. Not because of possible permeability, any loss there is probably negligible, imho. Switching because I feel like it will hold up better long term around connections, etc. It's a small price to pay for peace of mind.


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## jeffkrol (Jun 5, 2013)

burr740 said:


> Silicone tubing is not $1/ft. I've been using this stuff for a couple of years - Hagen Elite Elite Silicone Airline Tubing Aquarium & Pond Airline Tubing . Similar priced at any pet store.


so "normally" 60 cents a foot.. plus or minus..

2x the cost of PVC tubing..

Just need to add this for.. some...


> I realize this is thread is seriously old, but I think it's an important and timeless discussion.
> 
> My point: the math is off, because you're looking at gauge pressure instead of partial pressure. <1 psi is not correct. Conclusions from this thread are incorrect as a result. There is significant losses when silicone tubing is used, but many other tube materials are adequate.
> 
> ...


http://www.barrreport.com/forum/barr-report/co2-enrichment/5014-co2-tubing/page2
http://www.academia.edu/6754039/App..._by_diffusion_through_gas-permeable_membranes


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## Teebo (Jul 15, 2015)

Am I worried about the cost of losing CO2? - NO
Am I worried about paying more for tubing? - NO
Am I worried about potential buildup of CO2 in my small 10 x 10 bedroom? - MAYBE
Do I want peace of mind for longevity and lifespan? - YES
Do I overbuild/overthink every project I work on? - YES lol

I will avoid silicone and vinyl tubing, I would prefer black tubing. 



houseofcards said:


> Never had a problem with silicone tubing. How did it exactly fail? BTW the stuff sold on eebay is the same stuff sold on Amazon and countless other sites/stores, etc. I'm not sure why it's evilbay, when sellers there live and die by their feedback. Most go way beyond what other sellers might do to make buyers happy.


I am an eBay power seller, and we really do live or die on our feedback. Amazon has Prime, eBay has better service. Often they cross where eBay listings get delivered on Sundays via Prime (breaking policy).


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## houseofcards (Mar 21, 2009)

Although I've used everything from the cheap and hard Lee's Black Tubing I've also bought a few of the ADA Co2 tubing sets over the years. The grey actually looks pretty nice and is very soft and very silicone. This is the tubing and suction cups that comes with the co2 advance system.


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## jeffkrol (Jun 5, 2013)

houseofcards said:


> Although I've used everything from the cheap and hard Lee's Black Tubing I've also bought a few of the ADA Co2 tubing sets over the years. The grey actually looks pretty nice and is very soft and very silicone. This is the tubing and suction cups that comes with the co2 advance system.


They supply the silicone as to not break the glass "parts" Has nothing to do w/ permeability..
Easier to waste your CO2 than complain when you break their stuff...
Main "run" uses pressure resistant tubing ( hint: not silicone)









https://www.aquasabi.com/co2/co2-hose/ada-co2-pressure-resistance-tube-2-m



> Pressure-tight and CO2 resistant tubing
> Can be cut with a household pair of scissors without effort
> Suitable for push-pull connectors
> Do not use for connecting glassware


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## houseofcards (Mar 21, 2009)

I think we're on a different page. I'm talking about using the gray set to connect to glassware. That set is silicone.


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## jeffkrol (Jun 5, 2013)

houseofcards said:


> I think we're on a different page. I'm talking about using the gray set to connect to glassware. That set is silicone.


Understood. Thought you were trying to "infer" something more than apparently you were..

Just saying ADA uses silicone tubing to connect its glass bits.. It is certainly not sold by them as "CO2 resistant". That is their other tubing. 
To be honest, and to clarify, yes losses are, relatively speaking low and certainly not big $'s worth.
Point was losses escalate w/ pressure and distance from tank to output. 
All of this matters to "some"... be it purely scientific, or savings for one more other "thing" or even trips to the refiller..
Say someone runs 100ft of line to a distributor for multiple tanks. silicone CO2 losses can become "real"....

Point also was "CO2 resistant" tubing is as cheap or cheaper (depending on your source) than less CO2 resistant tubing.
Silicone IS nice and flexible though..

knowing what materials are and their strengths and weaknesses can make for better shopping..


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## houseofcards (Mar 21, 2009)

jeffkrol said:


> ...
> Say someone runs 100ft of line to a distributor for multiple tanks. silicone CO2 losses can become "real"....
> 
> Point also was "CO2 resistant" tubing is as cheap or cheaper (depending on your source) than less CO2 resistant tubing.
> ...


If I ever setup a tank on the top floor of the Empire State Building and I have to keep the cylinder in the basesment, I'll give you a call to consult :wink2:


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## PlantedRich (Jul 21, 2010)

So once again the never ending question that doesn't matter has been haggled to death so how about we move to something that does matter to many. The color? 
Quote: 
I will avoid silicone and vinyl tubing, I would prefer black tubing. 

This is one part where I do see a difference that might matter. Colors may be nice, depending on what appeals to each but then most of us might also like to think about performance? How can color change performance? 
It's often the little things that we miss that can come back to haunt us. One of those is the nasty habit of check valves failing. Check valves do a really big job and most of us do use them as we expect them to stand between the water and those really expensive little gizmos that should not get wet. Things like the needle valve, solenoid, and reg can all be damaged to various degrees when they get wet. It varies with different brands and styles but things like mineral deposits that dry in any of them will not help. 
One way I detect leaking check valves is by looking at the tubing! When I see water beginning to back too far into the tubing, I have to assume it is getting funky and I change it. 
Would I ditch the ability to see what's going on to get a more pleasing color? Not for me. 
I like a clear view of what's up so I prefer clear tubing.


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## Maryland Guppy (Dec 6, 2014)

Still playing with your hose?

Polyurethane would be a fine choice.
Use it for CO2, N2, and O2 in industrial environment up to 125psi.
O3 is another story, requiring specialty tubing.


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## houseofcards (Mar 21, 2009)

O.K. I think I'm done with the co2 tubing debate. It sounds a little like a Seinfeld episode. _The Thread About Nothing_


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## Teebo (Jul 15, 2015)

I think clear tubing outside the tank, between the check valve and canister is a good idea where it will stay clear (out of water) and serve as a functional window to check for water. Black or grey between check valve and diffuser could serve quite useful for appearance as long as its clear after the check valve. 

CO2 vs air pump check valve? I think there is a difference, because the stainless steel check valve I bought for CO2 does not work on even the highest pressure air pump I have.


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