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Re: [APD] CO2 problems (??)
oh excuse me I just posted the same time you did jerry... does your code
incorporate the same formula? I haven't looked at it really yet I just
assumed that since there was no input for temp.
On 3/2/06, Joel Fizette <sentientpuppet at gmail_com> wrote:
>
> 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*.
> > >
> > > Read the speaker list, then download the registration form, and get
> > > set 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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