# Pressurized C02 Components..I just don't get it



## Rnld (Jul 10, 2006)

Im planning to redo my tank, its gonna include a lot of plants. I have been reading on the forums here for a few days now and I am kinda convinced that Im gonna need co2... I have the money for a kit, and I think I am willing to invest in one. 

the only thing is, I dont get it. I see everyone talking about diffusers, reactors, needle valves... I just don't get it. 

Therefore I was wondering if someone could explain to me what every part of the co2 system does ( Maybe with a picture, Im very visualy focused  )

So please give me a hand here  


Thnx


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## Erirku (Oct 5, 2004)

Think of it this way. Forgive me, since I'm not a science freak. I just go with the flow, also.
In life, we humans and every living being, need oxygen. In the world, land plants (Forrest, ocean, Amazon) take in Co2, our byproduct and make large amounts of O2 for us to breath during, Photosynthesis. At night, trees take in O2 and give Co2. I think that's right???
So, for an aquascape to work, we use Co2, only when there is a high out put of light. For instance Compact Fluorescent or CF. If you are going low tech, then you might get by with no Co2 distribution, depending on what type of plants you are going to house.
IMO, it depends how well you are also. I have seen some wonderful aquascapes with no Co2, and it is a high tech tank, with alot of light. But those are for the experienced peoples, and I don't go there. So all in all, what type of aquascape are you goona do? Someone else might be able to key in on this, since there are more experienced people. Hopes this helps, and good luck .


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## misopeenut (Jul 10, 2006)

a co2 cylinder, thats where the co2 is stored. i think you know that already:wave:









a regulator, reduces and controls the pressure from the cylinder









a needle vavle, for more precise control, not needed but good to have.









a solenoid valve, to automate the co2 injection, works with timer to turn the gas on and off









a bubble counter, to find out how many co2 are going in the water









a diffuser, diffuses co2 into your water. reactor does same thing but in a different way

hope im not wrong on these..... and hope this helps


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## Salt (Apr 5, 2005)

Some of my own take/notes (hopefully it's helpful):

The cylinder contains the CO2. It's in there at around 800 - 1000 PSI at room temperature. We don't want to squirt CO2 into the tank at 1000 PSI. 

To reduce the pressure, we use an appropriately named "pressure regulator" or just "regulator." This reduces the pressure to around 40 - 100 PSI. Nice regulators will have a knob on the front that lets you adjust this. This reduced pressure is referred to as the "working pressure."

Again, we don't want to squirt CO2 into the tank at 40 PSI.  We need to reduce this down even further. The actual injection rate can be one to several bubbles of gas a second (depending on the tank size, whether or not it's aerated, open top, closed top, and other factors). So we use another device to get the gas flow down even more, the needle valve. It always has a knob on it to let you adjust it.

From this point, we don't just put the tubing in the tank water and let the bubbles pop out of the end. We want to _diffuse_ the bubbles so they dissolve into the water and form carbonic acid for the plants. It's up to the hobbyist how to do this... some use a "CO2 Reactor," which is usually some type of widened piece of pipe or tubing with a hole on it for the CO2 tubing; it may or may not be filled with some kind of filter medium (like those plastic balls). It usually plumbs in between the canister filter's output and the water return. Others use a "Diffuser," which is like an airstone, except for CO2. The diffuser usually goes directly in the tank with the CO2 tubing attached to it; no plumbing into filter tubing required. Recently, Tom Barr suggested that using a diffuser and placing it underneath the water return from the filter is superior to using a CO2 reactor because it delivers "micro bubbles" of CO2 directly to the plant leaves. Still others simply use a tubing attachment to inject the CO2 into the water going _into_ their cannister filter. Again, it's up to the individual hobbyist.

There's some other devices as well. There's the solenoid valve (or just "solenoid"), which simply attaches between the regulator and the needle valve. The solenoid acts as a kind of plug or stopper to the regulator. Unless it's plugged in, the solenoid is closed. Plug it in, then it opens. You can then plug the solenoid into a device called a "pH controller" which has a plug socket on it for the solenoid. You attach a pH probe to the pH controller, then stick the probe in your aquarium. If the pH without CO2 is say 7.2, and you want to inject enough CO2 to make the pH read 6.4, you set the controller to 6.4. When the pH falls below 6.4, it cuts power to the plug that the solenoid is plugged into, thus stopping CO2 injection. When it rises above 6.4, it restores power to the plug that the solenoid is plugged into, thus starting CO2 injection again. You could also plug the solenoid into a timer to switch the CO2 on and off; many people like to switch their CO2 off at night. Unless you are using a pH controller or timer, there's no reason to use a solenoid.


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## Rnld (Jul 10, 2006)

*Thnx*

Hey thnx a lot, I find it very usefull =D 
Thanks a lot


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## hoppycalif (Apr 7, 2005)

The solenoid valve is very useful without a pH controller - plug it into the same timer that turns the lights on. That way the CO2 is only going to the tank when the plants can use it, with the lights on. This saves CO2 and reduces the stress that high CO2 levels put on the fish.

One more thing: You can buy regulator combination units that have the regulator, needle valve, solenoid valve and bubble counter all hooked together, so installation is easier. That is what I use, the Milwaukee unit, and it works fine for me. But, the quality is not the highest, nor is the reliability the best. For the best quality and reliability you can get someone like Rex Grigg http://www.rexgrigg.com/sale.html to make up an assembly for you, using all top quality parts.


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## kimbm04r (Apr 22, 2005)

*Sticky*

I think this is great. I think it would be great to have it as a sticky.

Very informative to the person just starting planted aquariums and wanting to know about the use of CO2 and how to set up/use it.


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## diablocanine (Jul 25, 2004)

hoppycalif said:


> The solenoid valve is very useful without a pH controller - plug it into the same timer that turns the lights on. That way the CO2 is only going to the tank when the plants can use it, with the lights on. This saves CO2 and reduces the stress that high CO2 levels put on the fish.


Please explain this to me. I do not understand how using a controller can contribute to increased CO2 usage and higher CO2 levels. I disagree, using a timer will put more CO2 in the water than needed, a controller will not do that...DC


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## cwlodarczyk (Sep 18, 2005)

diablocanine said:


> Please explain this to me. I do not understand how using a controller can contribute to increased CO2 usage and higher CO2 levels. I disagree, using a timer will put more CO2 in the water than needed, a controller will not do that...DC


I believe he was responding to another post which claimed that the solenoid was useless without the pH controller. His counterclaim was that the solenoid could still be utilized without the controller by plugging it into the light timer thus saving CO2 at night when it not needed.


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## mazakman (May 10, 2006)

I know that this is not a sponsors site but this is a great deal. It has everything to get started except the CO2 bottle. I have 2 tanks and use this set up on both with no problems. http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=9935&N=2004+113779


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## Rex Grigg (Jan 22, 2004)

mazakman said:


> I know that this is not a sponsors site but this is a great deal. It has everything to get started except the CO2 bottle. I have 2 tanks and use this set up on both with no problems. http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=9935&N=2004+113779


It's really nice that they include silicone tubing which is the absolute worse choice for a CO2 system. Silicone can lose up to 6% of the CO2 per foot.


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## Salt (Apr 5, 2005)

cwlodarczyk said:


> I believe he was responding to another post which claimed that the solenoid was useless without the pH controller.


The point about the timer was very good and something I overlooked. I added that.


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## DJKronik57 (Apr 17, 2006)

Wow, this post is exactly what I was looking for, thanks!

What is the best tubing to use for CO2? I thought silicone was at least better than air-line tubing. Also, where does a manifold fall into that part order if one is splitting the CO2 between tanks?


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## Salt (Apr 5, 2005)

I've quoted this chart regarding gas permeability rates in the past, but I don't really know a lot about the units used or what it really means for the aquarist. I know that lower numbers are better:

http://www.coleparmer.com/techinfo/techinfo.asp?openlist=D,E,C&htmlfile=SelectingTubing.htm

Personally, I use clear vinyl, which has what I think is a pretty decent permeability rating. Some have said that it can harden and deteriorate over time, but I've been using the same vinyl tubing for the past year or so and it hasn't hardened. Besides, it's quite cheap to replace.

According to the chart, the material with the lowest (best) CO2 permeability rating is FEP, which is a clear semi-rigid tubing. I understand it's flexible plastic with a crystalline molecular structure like glass. Also according to the chart, silicone has the highest (worst) permeability for CO2.


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## Laith (Sep 4, 2004)

And since the original question was posted from the Netherlands, to convert PSI to bar (the metric measurement of pressure), divide PSI by 14.5.

Regulators you buy outside of the US normally measure in bar...


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## Rnld (Jul 10, 2006)

Good to see that I was not the only one looking for an explanation =D 
Thnx everyone for being so helpfull


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## Rex Grigg (Jan 22, 2004)

DJKronik57 said:


> Wow, this post is exactly what I was looking for, thanks!
> 
> What is the best tubing to use for CO2? I thought silicone was at least better than air-line tubing. Also, where does a manifold fall into that part order if one is splitting the CO2 between tanks?


I use polyurethane tubing. It's flexible and loses very little CO2.

A manifold would go here.

Cylinder - Regulator - Solenoid - Manifold - Needle valves


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## Rod Hay (May 6, 2006)

I second and third that! Great presentation on the info!

I'm a mechanical ignoramus and it took me several months of research, reading and many brain-aches before I thought I even had a clue what all the necessary hardware was.

Since someone has mentioned suppliers (being the mechanical dunce I also went the all-in-one route); I purchased this one:

http://www.aquariumplants.com/AQUARIUMPLANTS_com_s_Co2_Regulator_The_BEST_p/co2-1.html

This one doesn't come with the timer or tubing BUT it does have the needle valve & bubble counter already plumbed in. (I didn't see those listed in the Dr Foster's descriptions.) There were no instructions with the unit but when I called with my concern and anxiety they coached me thru the hook-up - step by step over the phone! My unit has been running carefree since February.

Now MY Tank, that's another matter....if I could just stop rearranging things.


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## mazakman (May 10, 2006)

Even ADG uses silicon tubing. http://www.adgshop.com/Gray_Parts_Set_p/101-506.htm The reason is if you use a lot of glass parts(diffuser, Pollen Glass Beetle counter) it's very easy to break them with hard tubing. It's a real bummer if you break your 100.00 glass part to save a dollars worth of CO2 .


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## Rex Grigg (Jan 22, 2004)

If you have several thousand dollars in a 30 gallon tank then I doubt that losing 25% of your CO2 is going to bother you.

Also just because women are mistreated by about 50% of the world's population of men doesn't make it right.


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## Salt (Apr 5, 2005)

The vinyl tubing works good on ADA glass parts. Use the 3/16 ID - 5/16 OD size and it will fit snugly without being too tight that you'll break the glass.


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## mazakman (May 10, 2006)

Hey Rex. Mellow out. This is about a fish tank hobby. Not about world strife


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## TheSentinel (Jan 25, 2006)

What is the role of a check valve? That's the only part I'm unclear on.


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## LordSul (Mar 17, 2006)

How long would a 500ml presurised CO2 tube last for a 10G tank??


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## agmurf (Jul 9, 2006)

If your worried about losing your gas, where I work the analyser people use tygon tubing. Looks like vinyl tubing but is sutable for lots of different gasses.

just my .2 cents worth.


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## John N. (Dec 11, 2005)

Sentinel, the check valve is used to prevent back siphoning of tank water down the CO2 tube. When this is installed stops the water from draining, and protects your regulator. Imagine as a 1 way tube, that allows only air to push though to the tank. No air or water can go the other way.

LordSul, 500ml CO2 tube longevity will vary on bubble rates. But expect to have it going for at least 1-2 months @ 2 bubbles per sec.

-John N.


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## Telperion (Jun 12, 2006)

Rod Hay said:


> I second and third that! Great presentation on the info!
> 
> I'm a mechanical ignoramus and it took me several months of research, reading and many brain-aches before I thought I even had a clue what all the necessary hardware was.
> 
> ...


I think I'll buy this one. Thank god for this thread -- pressurized CO2 confusion has been on my mind for a while. This helps soooo much. :hail: Now I just will have to buy a timer and tubing? Or maybe I'll hook it into the light timer as suggested. Where do folks buy tubing?

Also does anyone in the DC area have suggestions on where to find a CO2 supplier??


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## Rex Grigg (Jan 22, 2004)

Look in the yellow pages. 

Compressed gases

Welding supplies

My favorite Fire Extinguishers


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