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Well I just upgraded from DIY CO2 to a 10# tank. I have a two guage regulator and a needle valve. I hooked everything up, and started the CO2 bubbling. I had it down to about 5-10 bubbles per minute.

Everything seemed to be great, but after about 3 days, the tank was empty. Now when I first got it filled and hooked up the regulator, it read about 850 psi. Is that too low?

Also, I'm using normal clear aquarium tubing. I've heard mixed reviews - does CO2 really leak through this?

Any suggestions on how I can check for leaks?

Thanks,

Carl

Hi,
When I first started using my pressurized system, I too
went through a tank in a week. I discovered a crack in
the plastic check valve that is designed to prevent water
from flowing backwards into the regulator in the event the
tank runs out of gas and I'm not there to see it occur.

There are several points at which it can leak.
First, yes, the standard airline tubing can "leak" CO2
its length, but that is not the main reason for not using
it. Because of what it is constructed of, CO2 will cause
those lines to become brittle and crack. You should use
only the black CO2 approved tubing. You can purchase it
from where you got your tank, where you get your tank
refilled, or from any of the sites, such as Arizona Gardens.
com.

Take some sort of container, a glass or something, and
mix water with some liquid dish washing soap to make some
soapy water.

Get your tank refilled. When you connect the regulator
to the tank, wrap a turn or two of teflon tape (called
plumbers tape, found at any hardware store) around the
threads of the tank where the regulator attaches.
As you wrap the tape, pull on the tape gently so the
tape starts to sink into the gaps between the threads.
Too much and you will pull the brass through the tape.
Too little and it will rotate as you tighten down on the
brass collar.
When you wrap the tape, wrap it so that the
tightening action of the collar goes in the same
direction as the tape.
When the tank eventually runs out of gas and you remove
the regulator, remove all of the remanents of the tape
and when the tank is full retape it.

Next, back your regulator off all the way. You can feel the
resistance of the springs ease as you back off the main
regulator knob.
Now open your tank valve.
Now adjust your regulator for no more than 2 pounds of
pressure to the secondary side.
Now adjust your needle valve to provide the desired number
of bubbles/second. Normally, that will be around 1 per sec
to start with.

Now with everything assembled, and the system pressurized,
slowly drip or run the soapy water across EVERY fitting
and connection. Where you see bubbles, is where your
leak is.

Frank


Last edited by FRANK at 24-Apr-2005 10:55

Last edited by FRANK at 24-Apr-2005 10:58

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Thanks Frank,

The soapy water is just the trick.

I'll get my tank refilled tomorrow and try it again.

Carl


Almost forgot - so why is it that the liquid siphons back into the tank when it goes empty. That doesn't make sense to me.

Thanks again.

Hi,
If the tank is run completely empty, then a difference
in atmospheric pressure (high and lo pressure weather
fronts) can cause the water to syphon back into the
empty tank. A one way check valve in the line from the
output of the regulator to the reactor or diffuser
(which ever you use) will prevent that from occuring.
Actually, in the Navy, I was taught to never
run a tank completely empty and always leave 3-5 pounds in
it. That keeps the insides of the tank "dry" and prevents
rusting of the innards.



-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Thanks again Frank,

My leak was in the connection between the needle valve and the supply hose. It seems I've found yet another great use for aquarium sealant....

Carl