Pressurized co2 plumbing across a room

N

nerbaneth

Guest
Hi!

I am trying to plumb co2 across a room under the rug. I have two planted tanks on opposite walls and only one 10 lb CO2 tank. What is the best way of doing this? The owner of the LFS suggested that I should use that black drip line tubing that is used for irrigation so it will not pinch when people step on it. The tanks are about 10 feet apart.

I am concerned about three things:
Will the pressure of co2 in airline tubing or drip line stay at a similar or close pressure at 10 feet?​

If I am using the drip line tubing, how should I make it air tight around the brass Y connector that separates the two lines. For those of you who haven't used drip line: it has the nasty tendency to stretch and stay stretched unlike our trusty airline tubing. I was thinking about just using a small hose clamp.​

Is drip tubing even more permeable to co2 than airline tubing? So much that it is not even worth my time?​

My other options are:
Use regular airline tubing all the way around the room instead of across it so I don't have to worry about people stepping on the line. My concern for this is that the length of the line could exceed 20 feet and that the pressure drop would be large.​
Use some kind of pvc to go all the way around the room. I'm not sure what type of tubing to use for this. This is also the least desirable option because it is the most expensive.​

Is there anyone that has had this same or a similar problem? I was unable to find any forum posts. Any other ideas?

Thanks,
-Danny
 
Last edited:

Oreo

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May 6, 2010
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There really shouldn't be much of a pressure drop across the room. You could use a larger I.D. tubing though if you're really concerned. 1/4" ought to be plenty. Just try connecting a 20' coil of tubing and see if you're getting the flow you want before you run the line under the carpet.

As for running the tubing, I'd avoid going under the carpet if at all possible. That's asking for troubles with the tubing, the carpet looking nice, etc. The best place to run tubing like this would be behind the base molding. There should be just enough space there for you to run the tubing around the perimeter of the room. Behind crown molding might work also if you have that. And finally, if the floor joists are running in the right direction you could run the tubing inside and up the wall, then into the ceiling, across the room, back into the wall and down to your aquarium. Digging into the walls isn't for the light of heart, but that's the way I'd do it.

As for the kind of tubing, this is one instance where you probably do want to use something that's impermiable to CO2. The increased I.D. and the length of the run increase the potential for CO2 loss considerably. If you run the line in a location that isn't likely to be stepped on or messed with then you can go with a soft flexible tubing and be just fine. In that case you want 1/4" I.D. PVC tubing. (Same stuff all the planted-tank stores are selling only larger I.D.)
 

Oreo

Guru Class Expert
May 6, 2010
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That reinforced tubing is awful thick, O.D. It would definitely be more difficult to hide depending on how / where he plans on running it. It's also vinyl, not PVC which means higher CO2 permeability.
 

Left C

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Sep 26, 2005
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Reinforced Clear PVC Tubing Polyester Braid
Chemical resistant but also meets FDA standards and CFR Title 21 parts 170-199. Non-toxic, crystal clear, ozone resistant. Service temperature +25°F to 150°F. Self extinguishing. Heavy wall is kink resistant. Burst pressure 4 times W.P. 72 Durometer. Standard length is 100'. Tubing is priced per foot; sold in 10 ft. intervals only.

1/8" I.D. x .328 O.D. Reinforced Clear PVC Tubing Polyester Braid: http://www.usplastic.com/catalog/item.aspx?itemid=44400&catid=736

This one's OD is almost 1/3" vs 1/4" for 'normal' tubing. It's reinforced. PVC's permeability to CO2 is practically 0 (6.8 on the Cole-Parmer chart). It has the normal 1/8" Id and it's $0.27 per foot. Qty 100 ft: 5% off
 

S&KGray

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Nov 18, 2009
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Left C;50835 said:
Reinforced Clear PVC Tubing Polyester Braid
Chemical resistant but also meets FDA standards and CFR Title 21 parts 170-199. Non-toxic, crystal clear, ozone resistant. Service temperature +25°F to 150°F. Self extinguishing. Heavy wall is kink resistant. Burst pressure 4 times W.P. 72 Durometer. Standard length is 100'. Tubing is priced per foot; sold in 10 ft. intervals only.

1/8" I.D. x .328 O.D. Reinforced Clear PVC Tubing Polyester Braid: http://www.usplastic.com/catalog/item.aspx?itemid=44400&catid=736

This one's OD is almost 1/3" vs 1/4" for 'normal' tubing. It's reinforced. PVC's permeability to CO2 is practically 0 (6.8 on the Cole-Parmer chart). It has the normal 1/8" Id and it's $0.27 per foot. Qty 100 ft: 5% off

Nice find Left C!

Left C;50836 said:
Are you going to be running two needle valves and two bubble counters?
Good question, I was about to ask the same thing.
 

Biollante

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Jun 21, 2009
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Hi,

Left C found my link.

My house and out buildings are plumbed for CO2 delivery, we use rigid and reinforced tubing “beverage” grade stuff, very little tubing. In addition to those listed by Left C the advantages of reinforced include very low CO2 loss and drastic reduction in pressure fluctuation due to tubing. :cool:

Biollante
 

Left C

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Sep 26, 2005
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Biollante;50844 said:
Hi,

Left C found my link.
Nope ... Your link didn't list any 1/8" ID reinforced tubing and mine did.

tweety2.jpg
 
N

nerbaneth

Guest
Thanks for the replies and info!

In the past I ran it with one needle valve, a brass tee to split the line, and then one line had a cheap plastic 'air valve' (I wouldn't call it a needle valve even though it kinda is). It is difficult to get the balance between the two valves but, using co2 drop checkers and some patience, it can be done. Once it was set, I never had to adjust it again.

So.. Rigid beverage-grade PVC tubing is the way to go? The stuff on this page will work? http://www.coleparmer.com/techinfo/techinfo.asp?htmlfile=SelectingTubing.htm What are the disadvantages to using PVC "aquarium line" to that stuff? I'm in an apartment so no tearing out of walls can be done (As much as I would like to - for the pure joy of the look on our evil manager's face :) ) I am just going to run it along the baseboard although, I would prefer to run it underneath my rug for simplicity's sake.

Thanks again,
-Danny
 

Oreo

Guru Class Expert
May 6, 2010
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On a long run of thin vinyl tubing you'll get more CO2 loss to permeation that you normally wouldn't notice on a short run. If I were in your shoes though I think I'd just accept the CO2 loss as the cost of doing business. I say that because with a dull / blunted putty knife you should still be able to squeeze 1/4" I.D. (NON-braided / NON-reinforced, ie. the thin O.D. stuff) under the base molding. It will be snug getting it in there but there's usually a gap beyond the edge of the carpet tucked under the molding. This is a better solution to running the tubing directly across the room under the carpet, and your landlord will never know. Even if you run the tubing under the carpet directly across the room, the thinner the tubing the better to keep it as unobtrusive as possible.
 

hbosman

Guru Class Expert
Oct 22, 2008
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You wouldn't want to run it under the carpet. Even running something like coaxial cable sticks out like a sore thumb. I don't think the CO2 loss from using less than ideal material will translate to something that would translate into any significant extra cost. Use the easiest material to install and call it a day. So, maybe you spend $5.00 more in CO2 - BFD! :)
 

S&KGray

Guru Class Expert
Nov 18, 2009
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Garden Island
nerbaneth;50870 said:
Thanks for the replies and info!

In the past I ran it with one needle valve, a brass tee to split the line, and then one line had a cheap plastic 'air valve' (I wouldn't call it a needle valve even though it kinda is). It is difficult to get the balance between the two valves but, using co2 drop checkers and some patience, it can be done. Once it was set, I never had to adjust it again.

So.. Rigid beverage-grade PVC tubing is the way to go? The stuff on this page will work? http://www.coleparmer.com/techinfo/techinfo.asp?htmlfile=SelectingTubing.htm What are the disadvantages to using PVC "aquarium line" to that stuff? I'm in an apartment so no tearing out of walls can be done (As much as I would like to - for the pure joy of the look on our evil manager's face :) ) I am just going to run it along the baseboard although, I would prefer to run it underneath my rug for simplicity's sake.

Thanks again,
-Danny

That link was just to provide comparison info on the different types of tubing for CO2 permeability. I think you should go with the smallest diameter, thickest wall tubing that you can fit where you need to run it and fit on your connections. You don't need reinforced tubing because we are working with low pressures but it wouldn't hurt either, especially if there is the chance the tubing will be stepped on. The link that Left C provided is on the money, but if you have a source of "aquarium line" that you are sure is PVC, then that should be just fine because PVC is one of the least permeable to CO2 according to that table.
 
N

nerbaneth

Guest
Left C;50935 said:
Loop That's the same tubing that I linked in post #6 and S&KGray suggests in post #14 and Biollante originally suggested in post #3.

It's should work fine.

Perfect! I guess that settles it then. Thank you guys so much!
-Danny