Re: using pure oxygen?

[Craig Williams]

Just don't light a match near the tank. Of put anything flamable near where
the oxygen bubbles out it could spontaniously combust.

"Bill Schowengerdt" > wrote in message
...
> I am wondering if anyone has experance with bubbleing pure oxygen. I know
> it allows more tank loading, but wonder how it affects cycleing, etc?
> --
> Bill
>
> Please God, delete G Bush. NOW.

[Bill Schowengerdt]

On Mon, 8 Mar 2004 13:45:48 -0500, in rec.aquaria.freshwater.misc you
wrote:

>"Bill Schowengerdt" > wrote in message
...
>> I am wondering if anyone has experance with bubbleing pure oxygen. I know
>> it allows more tank loading, but wonder how it affects cycleing, etc?
>> --
>> Bill
>>
>> Please God, delete G Bush. NOW.
>
>The first thing that pops to mind is that it might make you very dependent
>on technology. One power failure, or delay in refilling the bottle and you
>could loose a lot of fish.
>

Goop point. However, in my case I would join the fish. That is why I
have oxygen so handy.
--
Bill

Please God, delete G Bush. NOW.

[NetMax]

"nanoreef" > wrote in message
ble.rogers.com...
> Bill Schowengerdt may have written:
> > I am wondering if anyone has experance with bubbleing pure oxygen.
>
> I doubt "bubbleing" oxygen will do much of anything. The bubbles won't
> be in contact with the water long enough. If you very slowly added
> oxygen useing a setup similar to those used for CO2 you might be on to
> something.
>
> I don't think that a high O2 will allow you to keep an overstocked
> tank. All the other problems, such as nitrates, will be the limiting
> factor. Even if your tank lacked O2 you could increase surface movement
to
> improve gas exchange.

My opinion exactly.

NetMax

[Michi Henning]

"nanoreef" > wrote in message
ble.rogers.com...
> Bill Schowengerdt may have written:
> > I am wondering if anyone has experance with bubbleing pure oxygen.
>
> I doubt "bubbleing" oxygen will do much of anything. The bubbles won't
> be in contact with the water long enough. If you very slowly added
> oxygen useing a setup similar to those used for CO2 you might be on to
> something.

I agree. There is a limit to how much oxygen can be dissolved in water.
The limit depends on the water temperature -- the warmer the water,
the less oxygen can dissolve. Once the limit (saturation point) is reached,
no more oxygen will dissolve, period. You can easily reach the saturation
point with an ordinary air stone. Pure oxygen is a complete waste of time
in this context, I suspect. And its expensive and reasonably dangerous.

Cheers,

Michi.

--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com

[Morten]

"Michi Henning" > wrote in message
...
>
> in this context, I suspect. And its expensive and reasonably dangerous.

Define reasonable, I would catagorize it as being very dangerous because
it's so strong an oxidant.

Have you ever seen a grill lighted with charcoal that has been soaked in
liquid oxygen, it explodes and only take 2 to 3 seconds to reduce the coal
to ashes...

It looks great though but please use a very long (4-5m) long stick and
approiate safeguards when lighting it...


Liqiod Oxygen (LOX) is very dangerous because it's capable of reducing
pretty much anything to ashes in seconds...


/Morten



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[Michi Henning]

"Morten" > wrote in message
...
>
> "Michi Henning" > wrote in message
> ...
> >
> > in this context, I suspect. And its expensive and reasonably dangerous.
>
> Define reasonable, I would catagorize it as being very dangerous because
> it's so strong an oxidant.
>
> Have you ever seen a grill lighted with charcoal that has been soaked in
> liquid oxygen, it explodes and only take 2 to 3 seconds to reduce the coal
> to ashes...

I've seen those photos. From what I remember, they sprayed LOX
onto the already lit BBQ. (Soaking the charcoal in LOX would do
a lot, I suspect.)

At any rate, I don't think we were talking *liquid* oxygen -- I suspect the
fish would complain about the cold... ;-)

Gaseous oxygen is nowhere near as dangerous (but still deserves a lot
of respect). You definitely don't want any open flame nearby. And
some substances spontaneously combust when exposed
to pure oxygen (such as grease in the fittings of an oxygen system).

Anyway, adding pure oxygen to a fish tank is likely to be a waste
of time, as far as I can see.

Cheers,

Michi.

--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com

[Bill Schowengerdt]

On Wed, 10 Mar 2004 13:13:15 GMT, In the heat of the moment, "Michi
Henning" > posted:
..
>"Morten" > wrote in message
...
>>
>> "Michi Henning" > wrote in message
>> ...
>> >
>> > in this context, I suspect. And its expensive and reasonably dangerous.

The O2 cost nothing since it is already being produced by by my O2
machine.

>> Define reasonable, I would catagorize it as being very dangerous because
>> it's so strong an oxidant.

It is only in a dangerous consentration in the small area at the top of
the tank. I cannot see any potential ignition in that area.

>> Have you ever seen a grill lighted with charcoal that has been soaked in
>> liquid oxygen, it explodes and only take 2 to 3 seconds to reduce the coal
>> to ashes...
>
>I've seen those photos. From what I remember, they sprayed LOX
>onto the already lit BBQ. (Soaking the charcoal in LOX would do
>a lot, I suspect.)
>
>At any rate, I don't think we were talking *liquid* oxygen -- I suspect the
>fish would complain about the cold... ;-)
>
>Gaseous oxygen is nowhere near as dangerous (but still deserves a lot
>of respect). You definitely don't want any open flame nearby. And
>some substances spontaneously combust when exposed
>to pure oxygen (such as grease in the fittings of an oxygen system).
>
>Anyway, adding pure oxygen to a fish tank is likely to be a waste
>of time, as far as I can see.


The main reason I used O2 was because it was handy. However, an airstone
produceing a given amount of bubbles of a given size will result in a
total surface area as the bubbles rise. With only small variations
between bubbling O2 and plain air.

A set amount and duration of surface area (or gas/water barrier area)
alows for only a set amonut of barrier crossing by O2 at a set O2
concintration..

If the O2 is highly diluted by other gasses, the amount of O2 exchanged,
will be MUCH less because less O2 is exposed to the barrier area, all
other things being equal.

All this is of course, altered by the saturation of the gases disolved in
the water. In this case it is safe to assume that the water is lacking
O2.

Thus... All else being equal... there is much to be gained by using O2.
--
Bill

Please God, delete G Bush. NOW.

[Morten]

"Bill Schowengerdt" > wrote in message
...
> The main reason I used O2 was because it was handy. However, an airstone
> produceing a given amount of bubbles of a given size will result in a
> total surface area as the bubbles rise. With only small variations
> between bubbling O2 and plain air.

If that's the case (O2 being handy and at low pressure) then adding O2 via a
airstone would be a good idea, but have you actually meassured the ammount
of dissolved O2 in the tank, it's quite easy to achieve 100% with a airstone
or two so it might not be necessary. It will give you better resistance to
temperature swings in the tank (the dissolvability (sp) of O2 decreases with
an increase in temperature) but if the temperature is stable then that
should not be an issue...


> A set amount and duration of surface area (or gas/water barrier area)
> alows for only a set amonut of barrier crossing by O2 at a set O2
> concintration..

The smaller the bubbles the better (for the same amount of air that is...)


> If the O2 is highly diluted by other gasses, the amount of O2 exchanged,
> will be MUCH less because less O2 is exposed to the barrier area, all
> other things being equal.

Highly diluted, normal air have about 20% oxygen in it...


> All this is of course, altered by the saturation of the gases disolved in
> the water. In this case it is safe to assume that the water is lacking
> O2.

Have you meassured the concentration of O2 in your system, you might be
surprised by the levels even with a standard airstone...


> Thus... All else being equal... there is much to be gained by using O2.

If it's handy like in your case, but if you hade to get it in bottles like
CO2 then i doubt very much that it would be worth he extra cost / trouble...


/Morten


> Please God, delete G Bush. NOW.

Cant' I'm busy on mondays...


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[Michi Henning]

"Bill Schowengerdt" > wrote in message
...

> If the O2 is highly diluted by other gasses, the amount of O2 exchanged,
> will be MUCH less because less O2 is exposed to the barrier area, all
> other things being equal.
>
> All this is of course, altered by the saturation of the gases disolved in
> the water. In this case it is safe to assume that the water is lacking
> O2.
>
> Thus... All else being equal... there is much to be gained by using O2.

Hmmm... I'm not sure I follow. What I know is that my (quite heavily)
planted tank is permanently at O2 saturation level, even in the morning
before the lights come on. There is so much O2 produced by the plants,
and so much O2 exchanged via the water surface, that any additional
O2 would simply bubble to the top without dissolving.

If you have a tank without plants, O2 might do some good, but I
suspect that you would do just as well by simply putting an air stone
or two into the tank and pumping air through them...

Cheers,

Michi.

--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com

[Geezer From Freezer]

I agree michi, ponds, rivers and the sea (although massive water disruption
there!) don't require
artificial o2. air stone would move the water in a sufficient way