Re: [APD] CO2 problems (??)

```actually jerry would you be willing to maybe make a modified version of your
calculator.js that incorporates this formula?

On 3/2/06, Joel Fizette <sentientpuppet at gmail_com> wrote:
>
> Has anyone made that into a calculator? because my tiny little brain
> doesn't seem to wan't to wrap around that every time I want to know my co2
> level... If no one has done so maybe I will write it myself.
>
>
> On 3/2/06, S. Hieber <shieber at yahoo_com> wrote:
> >
> > There might be some rickety tables out there ;-)
> >
> > There have been a number of formulas offered over the years that compute
> > roughly the same CO2 values under roughly the same parameters, even though
> > the formulas contain some very diff constants.
> >
> > I like the formula that was handed down after all the great discussion
> > by Paul Sears, and George Booth and Roger Miller, and Jeff Ludwig, etc..
> > This version is actually adjusted for a temperature of about 78-80 degrees
> > F:
> >
> > CO2 (in ppm) = 15.7*KH*10^(pKa(CO2/HCO3- system) - pH)
> >
> > generally                   =15.696*KH*10^(pKa-pH)
> > @ 78-80F                  =15.596*KH*10^(6.34-pH)
> > @ KH 9, pH 7            =15.596*9*10^(6.34-7.0 )
> >                                 =30.9 ppm
> >
> > KH 9, pH 7.0 => about 31 ppm
> >
> > I like this version because it directly incorporates the values for KH,
> > pKa of CO2 carbonate relationship, and pH, with only one assumed constant.
> >
> > The value for pKa changes with temperature although the changes are very
> > small. For example, at 70 degrees, pH7.0 and KH 9, the CO2 would be
> > about 33 ppm. Of course the diff between 31 and 33 is less than the compound
> > margin of error in doing home KH and pH measurements. ;-)
> >
> > If I've put things badly, there was a nice summing up of the points by
> > Paul in this post:
> >
> > http://fins.actwin.com/aquatic-plants/month.200207/msg00186.html
> >
> > sh
> >
> > * * * * * * * * * * *
> > The Northeast Council of Aquarium Societies (NEC) celebrates its 50th
> > year of service at its 31st annual convention, April 7-9, 2006 -- including
> > *An Evening with Aquarium Legends*.
> >
> > to join the fun at what promises to be the year's biggest tropical fish
> > convention.
> >
> > http://northeastcouncil.org/html/
> >
> > And while you're there, attend the AGA's annual meeting Friday afternoon
> > (2-4pm). This year's speaker is Claus Christensen, Tropica's Managing
> > Director.
> >
> >
> > ----- Original Message ----
> > From: Billionzz at aol_com
> > To: aquatic-plants at actwin_com
> > Sent: Thursday, March 2, 2006 1:05:16 AM
> > Subject: Re: [APD] CO2 problems (??)
> >
> >
> > >>>By the way, correct me if I am wrong but KH 9 and pH 7.0yields  about 27
> > ppm of CO2.  Not 170.
> >
> > I use the formula:  3*KH*(10^7-pH)
> >
> > That means 3*9*(10^0) = 3*9*1 = 27 ppm.
> >
> > Or am I  missing something?<<<
> >
> >
> > With a KH of 9 and a pH of 7 the CO2 would be 27.
> >
> > Here is the formula    3*KH*10^(7-pH)
> >
> >
> > Bill
> >
> >
> > _______________________________________________
> > Aquatic-Plants mailing list
> > Aquatic-Plants at actwin_com
> > http://www.actwin.com/mailman/listinfo/aquatic-plants
> > _______________________________________________
> > Aquatic-Plants mailing list
> > Aquatic-Plants at actwin_com
> > http://www.actwin.com/mailman/listinfo/aquatic-plants
> >
>
>
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