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Re: Mystery Tank



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>
>From: RicCooney at aol_com (Ric Cooney)
>Subject: Re: Mystery Tank



>I added the "Proper pH" by Aquarium Pharmaceuticals (not American
>Pharmaceuticals by the way) because my water was slowly dropping in pH. I am
>using DI water so I need to add trace elements, but the buffering was not
>keeping the pH steady.
>
Now the mystery deepens even more because you have been adding this stuff
from Aquarium Pharmaceuticals to raise the pH, and still you are titrating
with your CO2 kit a whole lot of chemical (probably NaOH) to get to the
phenolphthalein end point. I am assuming that your kits are using
phenolphthalien as the indicator die.  If you get a pink color, that is
what it is.  Is the ingredient in the Proper pH product, sodium
bicarbonate, or is it something like Na2HPO4 (sodium monohydrogen
phosphate)?  If it is the latter, I can see that it could act as a buffer
to  hold the pH below 8.  (The phenolphthalein end point is about 8.1) Try
this experiment.  Take a quart of tap water aerate and test for CO2 as
before, and then add some of the Proper pH product and test again.  If it
takes a lot more to reach the phenolphthalein end point, then we know where
the problem is coming from.  If you do get these expected results, then it
looks as though you can't use your CO2 kits if you also use the Proper pH
product.

Paul Krombholz                  Tougaloo College, Tougaloo, MS  39174
In chilly Jackson, Mississippi.