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Re: KH1 etc, related question (George)

> Date: Thu, 27 Dec 2001 16:38:32 -0000
> From: "George Booth" <gbooth at frii_com>
> Subject: Re: KH1 etc, related question (LONG)
> Slo-o-o-wly adding KH and CO2 with frequent water changes will become a
> hobby in itself. Probably not what you are after.

So true. I am NOT interested in turning my currently nice relaxing hobby into a chore.

> It sounds like you should leave well enough alone. If you want to use CO2 to
> help plant growth, you will have to deal with pH swings.  But, as pointed
> out by the fellows in San Francisco, fish aren't very sensitive to pH
> swings.

My understanding from others, & personal experience, is fish can take an upward pH change, even a
pretty large one, with no problems.
Sudden large swings down can be devastateing.
Leaving well enough alone is what I will do with the Discus tanks.

> For example, we do 50% water changes in our discus tank every other week.
> Our water has little KH so we add the right amount of sodium bicarbonate at
> each change. When we are through refilling and start the pumps to mix the
> sodium bicarbonate, the pH goes to 7.7 or so. The Ph controller will bring
> it back down to 7.0 within an hour. We have been doing this for 15 years
> with no observable problems. Does a change of 0.7 seem like a lot? It
> doesn't seem to bother the fish. Your results may vary.

0.7 doesn't seem like much to me. Particularly spread out over the coarse of an hour. If we were
talking about going from 6.0 to 5.3, I might think otherwise.
Lucky you for having soft water from the tap. I wish I was so lucky.

> Here is an important bit of information that most people seem to miss (but
> you seem to know about). Acid and acid buffers will lower pH by lowering KH.
> If you add KH for whatever reason then use something besides CO2 to lower
> the pH, you are simply destroying the KH you added. The only effect you are
> achieving to raise the sodium levels in your water.

Here's an odd story. I was in a LFS recently, owned & run by a gentleman who I always have
respected as a knowledgeable fellow. He has a fairly new display planted tank that seems to be
doing quite nicely. When I asking him about his CO2 injection technique, he said he quit using
gas because he had a problem with overdoseing & killing fish in the past.
He claimed that he was increasing the CO2 level in the tank by adding sodium bicarbonate AND some
type of acidic buffer, so that he chemically attained high KH and low pH.
This is very contradictory to my understanding of the pH / KH relationship. I figured the affect
of multiple chemicals would only raise the conductivity of the water.
I was going to tell him what he claimed to be doing was not possible, but I prefered to not try &
tell a businessman how to do his own business.
Is there any logic to what he claims to be doing?

David Modine