# DIY pressurized CO2 help



## saulat (Aug 7, 2009)

Ok a quick story of my walk down this road. Called all over looking for a CO2 tank and regulator, found one and bought tank and regulator. Clippard, and a local distributor for them, are in my general area so I drove out to the distributor and bought tubing, some adapters to fit my regulator, and the only needle valve they had. The needle valve was a larger Clippard and not rated as precisely in the catalog as the MNV-4K2. This valve did not work like I wanted, I believe I couldn't set the rate slow enough or when I did it would change on me. I also had 2 DIY bubble counters that simply did not work, for some reason I couldn't get them sealed so I bought a bubble counter. After receiving the bubble counter I ordered the MNV-4K2 to get some better precision. After getting the needle valve I called every place near me looking for an adapter for a 10-32 thread which is on the MNV-4K2. The tech guy at clippard gave me a bag full of adapters. I though great finally I can get my CO2 running. No, I kept getting fluctuations in the low pressure gauge, it would jump 5 PSI drop slowly down and then jump 5 PSI again. I would also set my bubble rate, come back and it would be much slower than before. Not sure what the issue here is so I took it all apart and tried to tighten everything. I had also noticed when looking for an adapter that the clippard casing comes off, the part where the barb is. I saw that there were two holes inside and figured those probably need to line up with the barb, although clippard told me it didn't matter. On tightening the needle valve onto the adapter on the regulator it snapped on me and now my needle valve is broken. 

Can anyone help me decide what needle valve to buy or know what the problem may have been in my system? I read something about pressure in the line but it doesn't seem like the issue to me. I have maybe 2-3 feet to the bubble counter and then another 4-5 feet of tubing. I am starting to lose my patience especially now with a broken needle valve and no idea what the problem is.


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## Seattle_Aquarist (Mar 7, 2008)

Hi saulat,

It may not have been your needle valve. It could have been leaks or the pressure. 

I use teflon tape on all my connections. The connections including the gauges, any adapter fittings between the regulator and the needle valve, and where the barb fitting goes into the output of the needle valve. I check all connections with soapy water after I have applied pressure. I also make sure that the valve on my CO2 tank is fully open. Then, with the needle valve slightly open, I adjust the output of the regulator to about 20 PSI. Let us know what happens.


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## saulat (Aug 7, 2009)

Thanks for the reply. I will let you know how it works and probably pick up some teflon tape tomorrow. This larger needle valve seems to be about the same as the MNV-4K2 except that the fluctuation on the gauge has stopped. The bubble rate still slows after some time.

Which teflon tape do you use? This site here says the regular white teflon is for water and a heavier yellow teflon tape is for gas line connections.

http://www.acmehowto.com/howto/homemaintenance/plumbing/general/teflon.php


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## Seattle_Aquarist (Mar 7, 2008)

Hi saulat,

I had some of the white teflon tape around the house so I used it and it worked fine. If I would have had to buy it I would have probably gotten the yellow. Using soapy water to check all the connections for leaks was the key to success for me.


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## saulat (Aug 7, 2009)

I added the Teflon tape today, haven't had time to try the soapy water. I did shorten the length of tubing I am using. I also have the tubing running straight into the water to see if maybe its some sort of back pressure pushing the valve closed. Next step I may take out the brass check valve to see if that helps, hopefully not destroying my regulator at the same time.


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## saulat (Aug 7, 2009)

Problem apparently solved by taking the tubing out of the power head. Ill verify that this caused it and come up with my next method of delivery. Not too sure I trust my canister filter intake until I get my drop checker. Think I may try the eheim internal filter that sounds like it works well.


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## Seattle_Aquarist (Mar 7, 2008)

Hi saulat,

A quality brass check valve may help you to avoid backpressure problems as well as the tank water siphoning backwards into your regulator. Brass is recommended because it is uneffected by CO2 unlike some plastics.


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## saulat (Aug 7, 2009)

Someone told me the tubing should be in the intake and not in the venturi intake. This is working fine for me. Not sure why the venturi causes problems and dont care cause it is working with even finer bubbles. I bought a brass check valve when I got my first needle valve, think its workin fine.


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## Seattle_Aquarist (Mar 7, 2008)

Hi saulat,

Glad to hear it! Let us know as things progress, CO2 really made a difference in the growth rate of my plants!


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## armedbiggiet (May 6, 2006)

saulat said:


> Someone told me the tubing should be in the intake and not in the venturi intake. This is working fine for me. Not sure why the venturi causes problems and dont care cause it is working with even finer bubbles. I bought a brass check valve when I got my first needle valve, think its workin fine.


That is a bad idea to put where the intake at. It would jam the damn thing when the power is cut not to mention it would make loud noices. I use venturi too and I know alot of people do the same but I had never hear any one do it from the intake though...:mmph:


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## saulat (Aug 7, 2009)

Its working great thru the intake. Not sure what the deal with the venturi is but the physics behind it must have caused back pressure forcing my valves closed. Even met a repiratory therapist today that I mentioned this to, he didnt have any idea off the top of his head. If the power goes out the co2 just collects and bubbles out in a big bubble, not really sure what you mean by saying it would clog??? Having some kind of ph kh issue, my drop checker is yellow so thinkin I need to crank down the co2 to a bubble a minute or less.


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## joshd (Oct 16, 2009)

Saulat -

If you don't mind the question. Using this diy pressurized method, what was your rough cost for the tank, regulator and the like?

I'd really like to try pressurized, but the cost is killing me!


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## saulat (Aug 7, 2009)

Well after finally getting the correct pieces and not counting mistakes I made. 

tank and dual gauge regulator - Around 80-100 I think
Needle valve - 10-20
tubing about 20 feet I think - 20
Connectors - Free basically
Bubble counter - 20 I think
Powerhead - 20 from Walmart
Check Valve - Maybe 10

Again running the Co2 into the venturi hole caused me lots of confusion and several wasted dollars on needle valves and headaches. If you can get a good seal you can make the bubble counter, got mine on ebay. Check valve was fairly cheap. Tubing, needle valve, and some adapters I bought from a clippard carrier locally. Got some free connectors from Clippard which is located here in Cincinnati. Got the tank and regulator from sparkling carbonics here in cinci.


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