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Hi guys,

I'm planning a planted 55g tank at the moment and eventually I will be putting a C02 system on.
My hubby is madly researching how to build his own system with a bottle of c02 rather than using the yeast in a soda bottle method.

I'm not sure of his plans exactly but he wanted me to ask will C02 have any effect on rubber if the two are exposed to each other?

Thanks for any help in advance.

Lindy

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Before you criticize someone walk a mile in their shoes. That way you're a mile away and you have their shoes.

Over time Lindy, the rubber will become brittle and start to breakdown. The Co2 acts like a "acid" and will slowly wear way at the structure of the rubber, causing it to break apart.

After awhile, you'll be injecting Co2 into the atmosphere and less and less will enter the tank. It would suggest using Co2 approved tubing.

Gary

Thanks for the quick response Gary.
I didnt think it would be such a good idea but told him I would ask anyway. I think he wanted to use it for sealing around the bottle itself and not as tubing. Either way i'm sure it will come in contact with the gas.
Oh well he'll come up with another idea shortly! (and drive me crazy whilst doing so) :%)

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Before you criticize someone walk a mile in their shoes. That way you're a mile away and you have their shoes.

silicone would be the best material if he wants to use something he can find easily. at least, that's what i've been told by others more knowledgable on the subject. where was he planning on putting the rubber to make a seal? the pressurized co2 requires a certain type of washer to seal the regulator to the bottle and then you can use silicone tubing or some other tubing rated for co2 from the regulator to the co2 reactor/diffuser/etc.

[span class="edited"][Edited by moondog 2004-09-07 09:45][/span]

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"That's the trouble with political jokes in this country... they get elected!" -- Dave Lippman

I'm not exactly sure what he's planning. Everytime I ask him about it he gets all excited and talks for an hour and I walk away with a numb head.

C02 sets from the lfs are very expensive so he wants to DIY it which is fine with me. The problem is that sourcing a C02 bottle elsewhere that we can purchase is practically impossible. Everywhere we go (welding shops, plumber accessory places) we are told to go lease one from a company that has a hold on the entire industry it seems. The other option is disposable C02 bottles but we havent been able to find any to purchase and they have an odd attachment aswell. The ones he has been looking at online are used in MIG welding?

His latest idea is to use a soda stream C02 bottle. These are cheap, not bad size wise, easily accessed and can be swapped over. The problem is that these bottles have a 'needle' that needs to be depressed to allow the gas out.
So he is trying to figure out something that can be attached to the thread on the bottle, depress the needle and be attached to a regulator.

Am I making sense?

Anyway, here are a couple of pics of what i'm talking about with the soda stream thing. He's been pondering for 2 weeks now.

EDIT: I'm not having any luck attaching pics atm, will post some soon...

[span class="edited"][Edited by Lindy 2004-09-07 22:48][/span]

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Before you criticize someone walk a mile in their shoes. That way you're a mile away and you have their shoes.

Hi,
Here in the states, we can purchase a new, empty tank
of any size, or, we can rent them. As he has found
you can purchase the empties from several sources online,
or simply go to the nearest "gas plant." By "gas plant,"
I mean a place that fills the tanks for wielders, or
a place that provides CO2 for bars, and restaurants, we
call them Tap sites.

You cannot ship those type of tanks, filled.
As was mentioned in a previous note, the CO2 will
eventually try out common hose, and that leads to cracks,
loss of pressure, and excessive use of the gas. Purchase
CO2 tubing from an aquarium site, or visit a beer & tap
store and get the hose from them. Commonly, here in the
states, CO2 "proof" hose is black in color and less
flexible than regular "airline" aquarium hose.

The system should consist of a regulator (preferably
dual stage) with a needle valve and two gauges (tank
pressure, and output pressure), a bubble counter,
and a reactor or diffuser.

To secure the connection between the regulator and the tank,
you wrap a turn or two of Teflon tape, (commonly called
"pipe tape" around the threads of the CO2 bottle and then
tighten the regulator with a wrench. The tape helps to seal
the connection without leaks, and not damaging the threads.

The tanks are seemless, stainless steel, or "just" steel.
They have a 5 year warranty, and then must be tested, or
certified doing a procedure called Hydrostatic Testing.
The shop that tests the tanks is government certified, and
once the tank it is tested, a dated is stamped on the
neck of the bottle. A tank that is out of date MAY NOT
be refilled until it is tested, and recertified.

Here in the states, I have my tanks filled at the local
beer&tap store. I pay a total of 9$ for 10 pounds, and
that amount lasts (at slightly over one bubble/second)
for 8 months.

With pressurized, or "bottled" systems, you are dealing
with deadly pressures. I have seen tanks go through
cinder block or aircraft hanger walls and then travel
across the runways. However, simple common sense will
prevent injuries. Use only parts specifically for
a pressurized system, seal the connections, and operate
your regulator ONLY as the instructions indicate.

In general, you wrap teflon tape around the tank threads,
and then attach the regulator with a wrench.
Then back off (counter clockwise) the regulator valve
( it will turn freely as the springs loose tension)
and close the needle valve.
Then open the tank valve.
The tank pressure gauge will now indicate the pressure
of the gas in the tank.
Then adjust the regulator to give you about 1 pound
of pressure, output.
If you have a bubble counter, and you should, now
adjust the needle valve for a bubble per second
(to start with).
Let the system run with one bubble/second and watch
the pH reading (I have a pH probe that connects to
a digital CO2 saturation meter). Plot the value
of the KH and pH readings on the chart and that will
give you the CO2 saturation in mg/l at any given time.
Shoot for something above 15mg/l and generally less
than 30mg/l. If your KH is above 3, then you can leave
the system run 24/7 as that KH will buffer the CO2
and the fish will be fine during the lights off part
of the daily cycle.

DO NOT use CO2 disposable cylinders such as those for
paint ball guns, etc. The volume of gas in them is
too small. Forming a safe, leak proof seal, for aquatic
purposes is very nearly impossible, and home made
holders are subject to catastrophic failure.

DIY CO2 systems are generally cumbersome when supplying
CO2 to tanks larger than 30 gallons. DIY systems
generally provide a tremendous surge of CO2 when freshly
mixed, and then as the yeast ferments (time goes by)
the amount of CO2 tapers off to nothing and a newly
mixed bottle must be added. This causes another surge,
etc. The result, since it cannot be regulated, is that
the pH drops with the surging input of gas, and then
rises as the production drops off, only to drop again.
The continuous rising and falling of the pH stresses
the fish, and can kill them.

Hope this helps some.
Frank


[span class="edited"][Edited by FRANK 2004-09-08 05:04][/span]

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

Thank you Frank. I have passed your information on to him. He says you have given him some things to think about.

I have not been able to find anywhere that will sell an empty bottle to us, they are all rental ones and I cant quite justify the price. (especially after reading some of the posts from people in the US etc)

If anyone else has anything to add, especially any aussies that have managed to set something up, please do so.



I'll be back with more q's soon!

[span class="edited"][Edited by Lindy 2004-09-08 07:12][/span]

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Before you criticize someone walk a mile in their shoes. That way you're a mile away and you have their shoes.

Canada as well has the buy or rent option. Using the "soda stream" bottles would be a disaster in controlling the output. How big of a tank are we talking about here Lindy?

Gary

Its a 55g tank. I think there may be problems with using the soda stream bottles too. The first being that we cant find a regulator to fit it. Adrian seems determind to find a way to use it safely though. *mumbles about stubborn men*
I'm currently chasing a few aussies that I know have C02 set up to find out where they got everything from.

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Before you criticize someone walk a mile in their shoes. That way you're a mile away and you have their shoes.

Hi,
The problem with the DIY system is the lack of control.
If you try to restrict the flow of CO2 from a newly
established "tank" of mix, it will burst the connections,
or even cause the 2 liter plastic bottle to explode.
Believe me when I say that is a mess one will clean up
only once!

If you two decide to go with CO2, then use a bottled
system. It is expensive to start, but very, very, easy
to maintain.

Frank


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