Re: Re: ph Control

[plasticolor@guate.net]

Cliff wrote:
>
>The charts are calculated with carbonate buffers because a
>H2CO3 -- HCO3 (-) + H+ -- CO3 (2-) + 2H+
>chemical system is what is actually responsible for the pH shift and
>buffering provided by CO2 injection.  KH provides the same buffering via
>Ca(CO3)2 as opposed to CO2, so your charts should be accurate.  Just
>remember that KH is a measure of ions that bond to carbonate... the
>carbonate itself does not make the water hard.
>
The charts express CO2 concentration (in mg/l or ppm) as a function of pH
and KH...  Does this mean that pH and KH regulate maximum dissolved CO2 ?
I am running in a new 55 gl. tank using peat as part of the substrate,
rather than using it as a filter media.  Plant growth rates (in combination
with clay, pumice - to prevent caking -, and gravel) are absolutely awesome
in this substrate.  I had to disconnect my yeast-CO2 supply, since pH was
reaching 6 and my KH=5 indicated - according to the pH/KH/CO2 table - that
CO2 levels should have killed everything in the tank.  However, my school
of Corydoras melanistus are doing perfectly.  I am now at pH=6.5 and KH=5
which, again, according to the table, should mean CO2 levels way above the
suggested maximum of 25 mg/l.  But the fish don`t show signs of distress.
Can I have lower dissolved CO2 levels than the table suggests for the pH/KH
values mentioned previously, because of the peat in the substrate ?

Peter
plasticolor@guate.net