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Re: CO2 system with/without pH controller

on 13/1/00 11:06 pm, Berryman, David at DBerryma at AspenMed_org wrote:

> I seemed to hit a nerve with the posting that I made a couple of days ago.
> I have received many response off the APD (which I appreciate, because some
> were not nice at all, others were very informative).

Hi David, and yes, that's the way it is with the APD sometimes :-) You must
understand that there are many here who are extremely passionate about what
they're doing ... take it easy :-) Anyway, I have some thoughts on this
issue which I would like to share with you.

> First let me give you a disclaimer.  I am not a biologist or a physicist.
> Having said this I do pay attention to details that have affected my tank.
> One undisputed fact no mater what anyone says is that when I measured the O2
> after over dosing with CO2 it was dangerously low.

I don't have your original post (its in the Mac at home, I'm in the office
now) but if I'm not wrong you never mentioned anything about KH and pH
right? So what makes you think that the CO2 is being overdosed?

I'm not disputing your facts, but the *facts* are, O2 and CO2 do coexist
together, and more of one doesn't mean less of the other. So now, we have to
analyse why your O2 levels dropped.

Fish gasp at the surface for many reasons. Nitrate and Ammonia poisoning are
some of them. High pH fluctuations are another. It's strange though, cos
normally when you *add* CO2, you make the water acidic, which turns harmul
ammonia to less-harmful ammonium. Heck, so now, I'm confused too! Maybe
someone else on the list can elucidate this better. All I'm saying is, there
are many other factors why fish gasp at the surface.
> When I set up a new CO2 tank and regulator I ran into the same problem and
> this time I turned the air stone up on hi immediately, and the fish had
> recovered within 15 minutes.  This evidence though you have not seen it
> yourself, speaks loudly that CO2 some how starves the fish of the O2 they
> need.

Well yes and no. Its not the CO2 that starves the fish. Rather its the
supersaturation of CO2 that does not allow the fish to "breath out" as it
were. In other words, the CO2 that the fish is trying to get out of its
system can't do so, cos the water is supersaturated with CO2. This however,
is nearly impossible to do if you have any kind of opening in your tank top!
As for your "evidence" of fish gasping, remember that they gasp because of
high chemical changes too, as mentioned earlier.

The more  Ithink of it, it sounds like Nitrite or Nitrate poisoning of some
sort. Again, I can't remember exactly why, but I'm pretty sure one of the
immediate cures is to aerate the water.

> For those of you that are pissed off at me for speaking of this I can only
> say TAKE A CHANCE if that is the only way to get you off my back and put
> your poor fish through this, although I would not recommend being cruel to
> your fish just to prove a point.  Maybe Mr. Booth or some one with a physics
> degree can explain it but the O2 that I would pump back into the tank DID IN
> FACT help the fish recover. That is undisputed proof in my book.

You don't need a physics degree to keep a planted tank David :-)
You *should* read a bit more about the subject though. I have it in the
recesses of my mind, and definitely in the books on my shelves at home, but
I can almost surely tell you that the symptoms you describe have something
to do with the condition of the *water* of your tank. The addition of CO2
just sort of accentuated the problem.

Now maybe I have opened another can of worms?

Mark Pan
Accept certain inalienable truths: Prices will rise. Politicians will
philander. You, too, will get old. And when you do, you'll fantasize that
when you were young, prices were reasonable, politicians were noble and
children respected their elders.
Baz Luhrman / Mary Schmich