You are at The Krib ->Plants ->CO2 [E-mail]

CO2 Regulator


  1. [F] Cheap CO2 regulator
    by (George Booth) (7 Nov 1994)
  2. Frogs, Cables, Vacation
    by George Booth <> (Fri, 28 Apr 1995)
  3. Regulated Flow Meter (for CO2)
    by "John Y. Ching" <> (Thu, 3 Aug 1995)
  4. FROG valves
    by (Dave Gomberg) (Thu, 25 Jan 96)
  5. Various
    by George Booth <> (Mon, 29 Jan 1996)
  6. FROG update
    by Tyson Lee <> (Thu, 8 Feb 1996)
  7. CO2 regulator valve
    by "Dave Gomberg" <> (Sat, 20 Jul 96)

[F] Cheap CO2 regulator

by (George Booth)
Date: 7 Nov 1994
Newsgroup: rec.aquaria,alt.aquaria,sci.aquaria

While waiting for my CO2 tank to be refilled at the local welding 
supply shop, I was browsing all the cool stuff related to the welding 
profession.  Mixed in amongst the plaid caps and kinky leather face
masks was a "FROG" - Flow Regulated Orifice Gauge.   It is a preset
regulator for CO2 tanks that is set to 22 PSI.  It has a little button
that either pops out or retracts when the tank is almost empty.  This
would be an inexpensive way to get setup with a more capable CO2
system.  It was marked $22 and is made by Western (Model RP22320).

George Booth                     "Nothing in the world is more dangerous than             than sincere ignorance and conscientious
Freshwater Plant Tank Technology         stupidity" - Martin Luther King, Jr. 

Frogs, Cables, Vacation

by George Booth <>
Date: Fri, 28 Apr 1995

> From: Erik Olson (e-mail)
> Date: Thu, 27 Apr 1995 19:36:22 -0700 (PDT)
> Subject: FROG
> George, the FROG is a little better than that, because it does have a
> little pop-out thing that tells when the tank is running low.  The label
> says "10 minutes left when it pops in".  But this is for welders who are
> not running it through a needle valve, so I'd guess you probably have a
> week before you have to actually replace the tank. 

A local store sells their own version fo CO2 injection using these
FROG things and 5# bottles and they report that they have *never* seen
the button do its thing.  FWIW.

Regulated Flow Meter (for CO2)

by "John Y. Ching" <>
Date: Thu, 3 Aug 1995

After buying a 15 lbs CO2 tank from a local fire extinguisher place, I 
have been searching for a good regulator and needle valve combination 
that's not too expensive. What I found was that any good two-stage dual 
gauged regulator used for welding cost anywhere between C$75 and C$160. 
I was also unable to find the fixed pressure FROG unit mentioned in the 
FAQ. I understand it doesn't have any gauge which is something I like to 
have. In terms of needle valves, the one George Booth recommended (Nupro 
B-4MG2) looked very solid but its C$59 cost is a bit expensive (why am I not 
surprised :-)). I also considered getting just a heavy duty valve, like 
the Parker valve suggested by Jamil Zainasheff, without the use of a 
regulator, but again I wanted to have something that had a gauge to tell 
me when the tank is about to go empty etc. 

Finally I found a gaget called a Regulated Flow Meter which is essentially
a regulator with an integrated needle valve control plus a flow rate gauge
in units of CFH (Cubic ft per hour?). Although the flow rate gauge is not
that useful for our purpose, I found that the integrated flow control is
very smooth and precise. I can get exactly one bubble per second without
doing much adjustment. It is rated for 3000 psi. There is also a
round dial gauge that gives you the pressure (PSI) inside the tank. The 
whole thing is made of solid brass. 

If you are interested, this thing is made by Victor Equipment Company of
Denton Texas, model # HRF1425-580. I paid C$90 for it, cheaper than a good
regulator+separate valve. And you don't have to look for different
connector and hoses to connect the two. That's about US$65 at the current
exchange rate. It may be cheaper in the States, especially if you have
better welding contacts than I do. 

 John Y. Ching (    |
 Pattern Analysis and Machine Intelligence Lab  | 
 Department of Systems Design Engineering       | 
 University of Waterloo, Canada                 | 

FROG valves

by (Dave Gomberg)
Date: Thu, 25 Jan 96

I talked to the FROG people and even got a data sheet.  The FROG is NOT A
PRESSURE REGULATOR, it is a FLOW REGULATOR (that is what the FR stands for). 
It is good in an application where it is the only component (other than the
tank shutoff valve) and is used to deliver its rated value (8CFH as I recall). 
It is not good where a regulator is needed because if you put something after
it intended to further reduce the flow, the pressure will just build up. 
Basically, a FROG is a pinhole, which thereby reduces the flow.  If you need a
regulator, you need a regulator, not a FROG.   Dave

Dave Gomberg, Experimenta      San Francisco CA USA


by George Booth <>
Date: Mon, 29 Jan 1996

> From: (Dave Gomberg)
> Tyson, if you doubt what I say, try tank+FROG+gauge+needle-valve in
> that order and close the needle valve.  The gauge will rise to 800PSI
> or so.  CFM is not pressure, it is flow.  The FROG is a Flow
> Regulator, not a pressure regulator.  Flow and pressure are highly
> correlated, stop the flow and the pressure will go through the roof.
> Don't injure yourself, use proper equipment.

Dave, this setup is being sold by a local shop and works very well, no
matter what the theory says.  

> From: Erik Olson <(e-mail)>
> Can normal needle valves withstand 800PSI of pressure directly?  I
> read a post on here or rec.aquaria once of a guy who didn't use a
> regulator at all, but just hooked a needle valve directly to his CO2
> bottle.  

The Dupla "Starter Kit" I started with lo these many years ago had a
needle valve that attached right to the CO2 bottle, a check valve, a
plastic diffuser doodad and some silicone tubing.  The needle valve
did just fine "regulating" the 900 psi bottle pressure although it was
a tad sensitive to adjust.   

George Booth in Rather Chilly But Sunny Colorado

FROG update

by Tyson Lee <>
Date: Thu, 8 Feb 1996

Just as other had told me, this setup seems to be working just fine after a
month or more in use.  I used a 5lb. bottle with a FROG attached.  From the
FROG, I used some compression fittings for the tubing/needle valve connections.
They leaked a bit, until I used more teflon tape.  They do not leak a bit now.

The only problem I had, was the temperature sensitivity of the needle valve.
The rate would fluctuate highly depending on the ambient temperature.  Once
the central was working again, this has become very minimal.

I had the tank refilled after it had emptied in about 3 1/2 weeks. (bubbling
was way too inefficient)  I have since tried to bubble it into some bells at
a much slower rate.  I should at least get about 6 weeks out of this refill
and more once I get this rate all figured out.  In the end, it cost me about
$90.00 for the whole setup.

I simply wanted to let Eric(cause he had asked how it was doing) and others
know that it _is_ working fine despite warnings about having my hand blown
off.  It sure beats the hell outta mixing that yeast.  Then again, I still
mix it for my other tanks. <sigh>

Up too late again,


CO2 regulator valve

by "Dave Gomberg" <>
Date: Sat, 20 Jul 96

Found a great vendor.  Amber Waves Brewing Supplies
2808 LaVista Road, Decatur GA 30033, 404-315-1100

$35 for a custom rebuilt regulator, ask them for 0-10PSI spring and
2nd stage gauge.  It will then be possible to reduce the pressure to
a low enough value to use regular air hose and valves for the rest of
the project, just like with an air pump.  No need for a special
needle valve.

Dave Gomberg, Experimenta      San Francisco CA USA

Up to CO2 <- Plants <- The Krib This page was last updated 29 October 1998