Pressurized CO2 tank problem

[Joey]

Hello folks,

I am a newbie to pressurized co2 injection and currently experiencing
some problem with
my setup. I acquired the following set of equipment:

1) co2 tank from welding shop for $55.
2) a single stage dual gauge regulator from Western Enterprised( order
from the same welding shop) $65
3) A Dwyster Flowmeter (Model# RMA-151-SSV) for $44

CO2 tank is connect to regulator. The low pressure output of the
regulator is connect to the flowmeter
using 3 brass NPT threads(Male-Female-Male) without any tubing. The
ouput of the flowmeter is
connect to a brass thread, which in turn can be connect to aquarium
tubing very tightly.

-----------------
Reactor

1) AquaClear Powerheads 402 by Hagen (from Petsmart)
2) A gravel-vac + about 1 feet of its tubing.
3) A wooden airstone

With the AquaClear Powerheads 402, there is an input hole in which an
airline for which an air pump
might be connected to the output of the powerhead. This supposed to
allow additional water+air mixing.
I decided instead of connecting it to an air pump, I connect it to my
co2 tubing. This setup seemed to
work only if I set my flowmeter to a very high flowrate (5-10+ bubble
per second). I realized this happened
due to the fact that I connected the output of the powerhead to the
gravel-vac tube. This increased the
water pressure within the tube and causing water to go up the "air
hole" of the powerhead (This doesn't happened if i do not connect to
the gravel-vac tube). Looking at the "air hole", I decided that it is
possible
for me to pull the aquarium tubing all the way out of the powerhead
output, into the gravel-vac tube, and further into the the gravel-vac
itself. Then I connected a wooden airstone to it. Hence,the airstone
is literately inside the gravel-vac. With this setup, I thought it
would be the same as bubbleing the co2 from
the bottome of the gravel-vac. At the open end of the gravel-vac, I
added some sponges.

I thought with this etup it would be like that of Chuck's setup:

http://www.csd.net/~cgadd/aqua/diy_reactor.htm

Still, after I adjust the co2 bubble rate to about 5 per sec. without
the powerhead on; the result is quite the
same. The result is that no bubble would appear after 1 or 2 minutes
after the powerhead is turned on. I believed the water pressure
somehow restricted the CO2 to bubble into the gravel-vac. This is true
with
or without the airstone.

And, it seemed that I have to increase more and more pressurized on
the flowmeter or the regulator in order to keep the CO2 bubbling out
of the airstone. What happened now in less than a week is that my
CO2 tank is empty. Also, once the high pressure gauge shown below
850psi, my tank would empty out in
a couple of hour. Before that, the pressure would drop about 200psi a
day. My tank was initally filled to about 1200psi.

I am wondering if anyone know what's wrong and whether the co2
supposed to be empty that fast. One thing about my CO2 tank is that I
bought it from this shop and the guy would exchange a tank for every
prefilled. I asked him whether the tank I bought is tested; he said
that as long as I refill my CO2 there, I don't have to worry about it.
I also asked him about the CO2 tank and how long would it last if I
use it for aquatic plants. He told me that he doesn't really know, but
he think it should last me only a couple of days.

I am wondering if anyone know what's wrong and whether the CO2
supposed to be empty that fast. I welcome any comments and advises.

Joe

[Poe Lim]

How big is your aquarium and your CO2 cylinder?

I have a 280L aquarium, and using a 750g cylinder and Dupla Reaktor 400, the
tanks lasted 3 mths (on a poor fill actually), keeping the CO2 at 20-30 ppm.
A lot depends on the efficiency of your reactor. I assume the sponge is not
packed tightly; if you do, the back pressure might be causing the problems
you are having. Also check for leaks in your CO2 tubing; I suspect that's
where your gas loss is.

Cheers,
Poe

"Joey" > wrote in message
om...

> I am a newbie to pressurized co2 injection and currently experiencing
> some problem with
> my setup. I acquired the following set of equipment:

[Rod Runnheim]

"Joey" > wrote in message
om...
> Hello folks,

That tank should last you at least 6 months, possibly a year.

If the bubbles are visible in the bubble counter, but NOT coming out of
your hose/reactor setup, this means that the air is leaking somewhere. If
it were back pressure, everything woudl equalize and the bubbles would stop.

You may want to immerse the entire setup in a bathtub or something and
find the leak that way.

Rod

[Poe Lim]

I'd say almost definitely a leak somewhere; I'm supplying a much larger
tank, with a cylinder 1/3 the size, that was improperly filled, for much
longer. Get some soapy water, and test your fittings. Might also invest in
some good CO2 proof tubes if you have long runs (but then some say it makes
no difference, so YMMV).

Cheers,
Poe

"Joey" > wrote in message
om...
> "Poe Lim" > wrote in message
>...
> > How big is your aquarium and your CO2 cylinder?
>
>
> My aquarium is 113L (30gals) and CO2 cylinder is 2268g (5lbs).
>
> Joe

[Chuck Gadd]

On Wed, 13 Aug 2003 03:16:46 -0500, "Racf"
> wrote:

>
>A couple of thoughts:
>
>1. Single stage regulators are cheap...and not as accurate as a 2
>stage....You paid 2 stage money....The one stage would show an accurate
>reading if you let the output bleed quickly while setting the gauge..

99% of planted aquarists who use compressed-CO2 setups are using
single stage regulators. They do the job perfectly fine. And while
$65.00 is a little high for a cheap reg, it's way below the cost of a
dual-stage regulator. And the dual stage regs are overkill for our
purposes.

>3. I hate trade-ins for things like this....It may be OK for a cutting
>rig that has all valves shutoff most of the time....but who wants a
>leaky old bottle

You are not going to get a "leaky" bottle. And for cutting, if the
valves were shut-off, you'd still have the leak, if it was the bottle.

The only downside to trade-in tanks are the physical appearance.


Chuck Gadd
http://www.csd.net/~cgadd/aqua

[Racf]

"Chuck Gadd" > wrote in message
...
> On Wed, 13 Aug 2003 03:16:46 -0500, "Racf"
> > wrote:
>
> >
> >A couple of thoughts:
> >
> >1. Single stage regulators are cheap...and not as accurate as a 2
> >stage....You paid 2 stage money....The one stage would show an
accurate
> >reading if you let the output bleed quickly while setting the gauge..
>
> 99% of planted aquarists who use compressed-CO2 setups are using
> single stage regulators. They do the job perfectly fine. And while
> $65.00 is a little high for a cheap reg, it's way below the cost of a
> dual-stage regulator. And the dual stage regs are overkill for our
> purposes.

Yes, he paid too much for a single stage regulator... Way below?

>
> >3. I hate trade-ins for things like this....It may be OK for a
cutting
> >rig that has all valves shutoff most of the time....but who wants a
> >leaky old bottle
>
> You are not going to get a "leaky" bottle. And for cutting, if the
> valves were shut-off, you'd still have the leak, if it was the bottle.
>
> The only downside to trade-in tanks are the physical appearance.

Chuck, the valve stems can leak just like an old faucet when turned
on.....and they do all the time....Its just a natural thing....
I am just saying look out, you definately do want one that leaks as
little as possible around the valve stem....since it will always be
turned on....

>
>
> Chuck Gadd
> http://www.csd.net/~cgadd/aqua

[Chuck Gadd]

>Chuck, the valve stems can leak just like an old faucet when turned
>on.....and they do all the time....Its just a natural thing....
>I am just saying look out, you definately do want one that leaks as
>little as possible around the valve stem....since it will always be
>turned on....

I've probably been thru 20 or so "trade-in" tanks, between my tanks,
and tanks I'd set up for friends. I have had some nasty looking CO2
tanks, but not one of them has had a leak around the valve stem, if
the valve was opened all the way.


Chuck Gadd
http://www.csd.net/~cgadd/aqua

[Jeff Lowe]

"Chuck Gadd" > wrote in message
...
> >Chuck, the valve stems can leak just like an old faucet when turned
> >on.....and they do all the time....Its just a natural thing....
> >I am just saying look out, you definately do want one that leaks as
> >little as possible around the valve stem....since it will always be
> >turned on....
> I've probably been thru 20 or so "trade-in" tanks, between my tanks,
> and tanks I'd set up for friends. I have had some nasty looking CO2
> tanks, but not one of them has had a leak around the valve stem, if
> the valve was opened all the way.

Chuck this is a very good point.
Long ago in my welding class we were taught that gas cylinders have a double
seat valve. The first seat is what closes the gas in when it is tightened
all the way down. The second seat is when the valve is opened fully and
seals the valve stem. _Always_ open the valve fully against the second seat
leakage around the stem will occur.
Jeff

[Joey]

Hi all,

Thanks for all the feedbacks. They are very informative. After, my
tank was empty, I went to a second shop and trade in my other tank. I
screwed in every threads very tight this time with teflon tapes. I
hope that it will last me at least a month this time.

Any how, my current problem is with the reactor. As stated in my first
posting, I am using the modified gravel-vac reactor with the powerhead
to pump the water into the gravel-vac. What I find trouble some is
that I tuned my flowmeter in such a way that it will output a 10-15
fine bubble per seconds. However with this setting, the bubbles
eventually doesn't come out. Hence, it is very hard for me to control
the CO2 concentration. I have to occasionally come and increase the
bubble rate a few times every day.

Yesterday, I turned bubbles rate a bit higher, thinking that the
bubble rate will slow down by the night time.
Any how, a stragic event had occured in my tank during the night. The
pH I tested this morning was 6.0 or below; and I believe that it had
shoot up my CO2 concentration to at least above 24ppm. I have to sadly
reported that all of my buddies, 8 cichlids, 6 octos, and 1 plecos
have passed away over the course of the night. As for fishes, I will
wait and make sure that this won't happens again before I acquire
anymore.

As for my diy reactor, I do not have any bio balls just a sponges
covering the open end of the gravel-vac. As I am typing this my bubble
coming out of my wooden airstone has again disappear. I wonder whether
this is cause by the water pressure coming into the gravel-vac or
whether the CO2 is actually dissolve so efficent that I am not suppose
to see any.


Any comments on this would be great.

Thanks,

Joe

[Chuck Gadd]

On 14 Aug 2003 12:26:07 -0700, (Joey) wrote:

>Thanks for all the feedbacks. They are very informative. After, my
>tank was empty, I went to a second shop and trade in my other tank. I
>screwed in every threads very tight this time with teflon tapes. I
>hope that it will last me at least a month this time.

Don't just hope. Add a few drops of dish soap to a cup of water, mix
it up, and brush the mixture onto all the fittings. No sense wasting
a whole tank of CO2 just hoping.

>Any how, my current problem is with the reactor. As stated in my first
>posting, I am using the modified gravel-vac reactor with the powerhead
>to pump the water into the gravel-vac. What I find trouble some is
>that I tuned my flowmeter in such a way that it will output a 10-15
>fine bubble per seconds. However with this setting, the bubbles
>eventually doesn't come out. Hence, it is very hard for me to control
>the CO2 concentration. I have to occasionally come and increase the
>bubble rate a few times every day.

I've got no idea about your flow meter, but from your original
message, if the co2 flow stops when you start the powerhead, then I'm
guessing that there is a leak, and once there is any pressure in the
gravel val, it's easier for the CO2 to find it's way out of the leak.

>As for my diy reactor, I do not have any bio balls just a sponges
>covering the open end of the gravel-vac. As I am typing this my bubble
>coming out of my wooden airstone has again disappear. I wonder whether
>this is cause by the water pressure coming into the gravel-vac or
>whether the CO2 is actually dissolve so efficent that I am not suppose
>to see any.

Try removing the airstone. Then you will be able to more accurately
see and count the bubbles. The larger bubbles coming out of the tube
should still dissolve properly in the reactor.


Chuck Gadd
http://www.csd.net/~cgadd/aqua

[Joey]

Okay, I did sprayed some soap solution on all the fittings. So far, no
sign of leakage. I did cut one of the aquarium tube ending so that it
fit tighter to my check valve. I also removed the airstone.

After setting the bubble rate 1 per sec., I came back about 2 hours
later. There is no more bubbling. I check the ph, it is now 8.0. I
will readjust the bubble rate again to see what will happens in a few
hours. I will keep you all posted on this.

Joe


Chuck Gadd > wrote in message >...
> On 14 Aug 2003 12:26:07 -0700, (Joey) wrote:
>
> >Thanks for all the feedbacks. They are very informative. After, my
> >tank was empty, I went to a second shop and trade in my other tank. I
> >screwed in every threads very tight this time with teflon tapes. I
> >hope that it will last me at least a month this time.
>
> Don't just hope. Add a few drops of dish soap to a cup of water, mix
> it up, and brush the mixture onto all the fittings. No sense wasting
> a whole tank of CO2 just hoping.
>
> >Any how, my current problem is with the reactor. As stated in my first
> >posting, I am using the modified gravel-vac reactor with the powerhead
> >to pump the water into the gravel-vac. What I find trouble some is
> >that I tuned my flowmeter in such a way that it will output a 10-15
> >fine bubble per seconds. However with this setting, the bubbles
> >eventually doesn't come out. Hence, it is very hard for me to control
> >the CO2 concentration. I have to occasionally come and increase the
> >bubble rate a few times every day.
>
> I've got no idea about your flow meter, but from your original
> message, if the co2 flow stops when you start the powerhead, then I'm
> guessing that there is a leak, and once there is any pressure in the
> gravel val, it's easier for the CO2 to find it's way out of the leak.
>
> >As for my diy reactor, I do not have any bio balls just a sponges
> >covering the open end of the gravel-vac. As I am typing this my bubble
> >coming out of my wooden airstone has again disappear. I wonder whether
> >this is cause by the water pressure coming into the gravel-vac or
> >whether the CO2 is actually dissolve so efficent that I am not suppose
> >to see any.
>
> Try removing the airstone. Then you will be able to more accurately
> see and count the bubbles. The larger bubbles coming out of the tube
> should still dissolve properly in the reactor.
>
>
> Chuck Gadd
> http://www.csd.net/~cgadd/aqua

[Chuck Gadd]

On 15 Aug 2003 12:48:24 -0700, (Joey) wrote:

>Okay, I did sprayed some soap solution on all the fittings. So far, no
>sign of leakage. I did cut one of the aquarium tube ending so that it
>fit tighter to my check valve. I also removed the airstone.
>
>After setting the bubble rate 1 per sec., I came back about 2 hours
>later. There is no more bubbling. I check the ph, it is now 8.0. I
>will readjust the bubble rate again to see what will happens in a few
>hours. I will keep you all posted on this.

At least temporarily, try it without the check valve in the path.
I've seen problems where check-valves restrict the flow too much, and
produce unstable CO2 rates.


Chuck Gadd
http://www.csd.net/~cgadd/aqua

[Joey]

Hi all,

Just to update with what's going on with my CO2 injection, so far the
CO2 bubbling rate is still at 1 per second since I set it yesterday
afternoon. This morning, I look at the bubble it is still going strong
at 1 per sec. and the pH reading is 7.0. I guess the fitting between
my valve and the tube in the tank was sort of loose.

Thank you all for all the feed back.

Joe