# needle valve issue?



## davemonkey (Mar 29, 2008)

I have an Azoo regulator that is factory set for working pressure. My tank has 950+psi and the working pressure is about 24psi. I adjust the needle valve to a certain level, but nearly every morning I have to bump it up a bit to get CO2 flowing at that same rate. It just slowly slows down almost daily.

First I had the output going to a powerhead and thought there was not enough end-pressure to keep the rate constant, so I got a Diffusor5000 from GreenleafAquariums (thanks Orlando, for super fast shipping and awesome packaging!! ...shameless plug) . But that hasn't helped. The rate of CO2 output still slows over a relatively short time frame.

Here's a pic. I did not get it from this website, but it's the only pic I could find.
http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+3747+9895&pcatid=9895

Any suggestions?

-Dave


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## Newt (Apr 1, 2004)

Wow, >950psig! Typical is 800 psig.

So let me get this straight. You are unable to adjust the regulator?

If you are able to adjust then back off on the regulator pressure and open the needle valve a tad more. You need to find a good balance. Temp fluctuations, I think, is the culprit.

I cant believe how high members a say they have their regulator set for> 15 to 25 psig. Mine is 1 psig but my needle valve is off off an expensive piece of equipment. It was on a thermal imaging device and was used to flow argon.


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## davemonkey (Mar 29, 2008)

Newt, I took a closer look and it's closer to 925, but definitely over 800. It's a 10lb tank and the guy filled it with 9 lbs liquid CO2 (he left the extra space for expansion, so he says) .

Anyhow, no, I cannot adjust the regulator. There is a nut at the top, and what appears to be a hole closer to the body where an allen wrench may fit. But, the instructions (the English part at least) say to never attempt to adjust the pressure.


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## Newt (Apr 1, 2004)

The cylinder size doesnt matter for the pressure. They are supposed to max out at 60% volume for liquid CO2. I have 5#, 10# and 20# and all are ~800 to 850 psig when full unless yours is rather warm.
My philosophy on guages has always been: 50% are broken, the other 50% are inaccurate.

I wouldnt adjust it if they give you a warning.


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## davemonkey (Mar 29, 2008)

Newt said:


> T
> My philosophy on guages has always been: 50% are broken, the other 50% are inaccurate.


 Too true.

This problem is what sparked the poll I put up asking whether people ran their CO2 24/7 or not. Now that I see at least 3 who run pressurized 24/7, and spoke to a 4th, I'm going to try that to see if the output will stay constant.

I just reduced the output to half what it was so I don't wake up to floating fish in the morning. Then, I'll start adjusting gradually. Hopefully this takes care of the fluctuating output.

-Dave


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## jmontee (Feb 7, 2008)

Dave, are you using solenoid with this setup?


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## davemonkey (Mar 29, 2008)

jmontee said:


> Dave, are you using solenoid with this setup?


Jorge,

Yes. I'm not sure what brand, it came factory installed with one. The only obvious problems I've had with it were 2 times when the power went out. The solenoid did not open back up until I unplugged and re-plugged it to the socket (which was on a timer).

-Dave


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## jmontee (Feb 7, 2008)

It sounds like you are having an issue with the solenoid closing completely. Does the CO2 stop completely when the solenoid closes? What time does it open in the morning? I have noticed issue with the bps slowing down when I close the needle valve during WC's but after a few minutes of warm up it settles in. Then I set it and forget it until the next water change.


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## davemonkey (Mar 29, 2008)

I had it set to shut off at 8pm and back on at 10am (with the lights) . The CO2 flow stopped completely when it was shut. Yesterday I plugged it directly to an outlet to let the CO2 go 24/7 and reduced the output. I'm going to let this go a couple days and see if the output changes any.


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## jmontee (Feb 7, 2008)

How much did you slow down your bps? I noticed that when I had mine going 24/7 it really wasn't a big difference in bps. Maybe 1/2 a bps so now I am going at about 1.5bps and I was good at 1bps using an inline rex grigg style reactor. I also have a good bit of surface disturbance with the spray bar from my canister filter. Be careful that you are maintaining enough during the day and I wouldn't worry too much about night time.


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## davemonkey (Mar 29, 2008)

I don't really know. Since I switched to the ceramic diffusor I stoped counting bubbles and just watch the 'fizz-output' from the ceramic. I made fizz less. So far the fish seem happy and the plants are still pearling, so I guess that'll be good for now.


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## intothenew (Aug 1, 2008)

I don't know if this is the problem but, I have found that a needle valve will give more consistent results if you open it considerably and then slowly close it. This takes care of any problems with lash in the threads, possible resiliency in the seat, and any deformation that may be in the packing.

Is there a gland nut that you can tighten?


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## davemonkey (Mar 29, 2008)

intothenew said:


> I don't know if this is the problem but, I have found that a needle valve will give more consistent results if you open it considerably and then slowly close it. This takes care of any problems with lash in the threads, possible resiliency in the seat, and any deformation that may be in the packing.
> 
> Is there a gland nut that you can tighten?


I'll do that (open wide and slowly close) if it looks like there is still a 'reducing output' trend. I'm not sure about a "gland nut" . I'll take a close look tonight to see what is what.

-Dave


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