Re: [AGA-Member] Co2 problems!

["S. Hieber" <shieber@yahoo.com>]

First thing is to get some soapy water and check for leaks
at the regulator, the needle valve, all the connections.
Leaks, even small ones can make it next to impossible to
get balanced settings on the regulator and needle valve. If
you find a leak, take care of it.

Next, check whether the needle valve is really the limiting
device or the regulator is. What is the pressure reading on
the low-pressure (output) side of the regulator.

What I have in mind is this, when you have the regulator
set to some open position--i.e., so that gas is flowing,
and you have a limiter downstream ,say, a needle valve, and
you close the needle valve down to reduce flow, then the
pressure between the regulator and needle valve increases a
bit do to the increased flow restriction from the needle
valve. When that pressure increases, the flow through the
valve increases a bit.

The other way around, the same thing can happen in the
opposite direction. You open the needle valve a bit to
increase flow -- but then the pressure between the
regulator and the needle valve decreases slowly, and the
gas flow slowly decreases, too. In these cases, the needle
valve is basically acting like a controller of the pressure
between the regulator and needle valve but the regulator is
actually doing the ultimate control of the gas flow. What
you want is for the needle valve to be the major
controlling factor. Above a certain pressure, for a given
system, increased pressure on the needle valve will not
cause an increased flow of CO2. If this is the problem,
then what usually works is to increase the regulator output
pressure and adjust the needle valve.  *Then* readjust the
valve again after the things have seemed to stabilize. If
the flow subsides again. Then increase the regulator output
a tad more and repeat the needle valve readjustments in
small amounts until things settle down. An iterative
process. On less expansive regulators and needle valves,
things can be fussier due to greater stiction than with
more expensive parts. But once the system is stable, even a
very inexpensive system can prove adequately stable and
reliable.

I know this is a pita, but it generally only has to be done
once and from then on you can use needle valve adjustments
on the rare occasions when you need slight adjustments (for
example, open the valve a teeny bit more n winter when the
average room temp drops down about 20 degrees F lower than
average summer temps) and otherwise not need to bother with
the settings. when you change out the tank for a refill,
don't fuss with the regulator and needle valve settings if
you can avoid it. Just turn off the main tank valve, slowly
loosen the retaining nut to remove the regulator, and
replace with a filled tank.

Watch the low pressure gauge on the regulator, if the
needle bounces ever so slightly whenever a bubble is
released at the end of the CO2 line, then you probably have
the regulator set to low.

Once you have the big swings in output tamed. Then you can
consider that changes in room temperature can cause small
changes in how the regulator performs and on the gas
pressure inside the CO2 tank. The changes will usually come
in small incremental shifts because the regulator mechanism
has some stiction both when opening up and closing. These
small changes shouldn't be a concern, but if you try to
tune things tune finely, and you room temps vary, you can
drive yourself needlessly nuts.


And remember, this is all still easier than trying to get
balanced sprinkler flows for outdoor, terrestrial gardening
;-)

Hope that helps,
Good luck,
Scott H.

--- matt scarnecchia <colonel594@hotmail.com> wrote:

> Hello all, My name is Matt and Im fairly new to this
> orginazation but it is 
> a pleasure to find and be a part of it. I'm having a
> problem with my newly 
> set up pressurized co2 system. A few weeks ago I ordered
> a AZOO pressure 
> regulator with magnetic valve, and needle valve. After it
> arrived I went to 
> a local welding supply house and picked up a 5 lb. co2
> tank went home and 
> set it all up. I adjusted the co2 flow to the desired
> amount and all seemed 
> to be working great and continued to work so for about a
> week or so.
>       Any way about a week later i was observing things
> and noticed that the 
> amount of pearling in the aquarium had decreased so i
> checked over some 
> things to find out that the problem appeared to be that
> less co2 was being 
> released from the regulator. So i checked things out
> there were no leaks, my 
> check valve on the air line tubing is working fine but
> still for some reason 
> a lesser amount of gas being released.
>      Not knowing what the problem could be i adjusted the
> needle valve 
> opening it a bit more to get the desired bubble flow
> (around 3 bubbles a 
> second or so) and it continued to work fine for the rest
> of the day. At 
> night the lights shut off and so does the timer for the
> co2 valve, and in 
> the morning it comes back on with the lights. So i
> figured I better check 
> things out to make sure it was still working properly
> only to find that the 
> flow rate had slowed down again to almost nothing....
> maybe about 1 bubble 
> about ever 5 to 10 seconds. Not my desired level. Baffled
> by what appeared 
> to be happening over night I checked ever thing over
> again looking for leaks 
> making sure all was hook up tightly with still the slow
> flow I went ahead 
> and opened the needle valve further back to the desired
> flow rate and once 
> again things worked fine for the rest of the day. at
> night everything shut 
> off, and in the morning when it all came back on I
> checked things out to see 
> what was going on.... with the same result as the day
> before.... for some 
> unknown reason the flow rate has slowed to almost nothing
> at all. I cant 
> figure out what would be causing this? has anyone else
> ever had any problems 
> similar to this? or have any idea at all what could be
> causing this strang 
> decrease in my flow rate after the magnetic valve shuts
> off and then comes 
> back on in the morning?
>      From what I under stand I should be able to set the
> needle valve to a 
> desired rate of flow, and every time that the magnetic
> valve opens again it 
> should resum at that flow rate making it all fine to be
> left alone every day 
> until the tank needs refilled..... and I cant figure out
> why things would be 
> acting in the way that they are..... Any help at all that
> could be offered 
> would be GREATLY appriciated..... I am fianally getting
> things with this 
> aquarium to a point that I am really pleased with it
> all.... but this has 
> been testing and rather frustrating to say the least....
> espically after 
> spending a very nice sized piece of change on this
> equipment to get the 
> desired co2 levels i wanted in my tank with out having to
> do daily maintance 
> to achive it..... thanks a lot for any help you can all
> give me!
>     Sincerely,
>          Matt Scarnecchia
>           Youngstown, Ohio
> 
>
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