Herdis Schopka

I have a really basic question: How does SpecE8 calculate TDS? The value for TDS that I get from SpecE8 are consistently higher than the ones I get summing up the concentrations of input species (Na+, K+, Mg++, Ca++, Cl-, SO4--, HCO3-, SiO2(aq)), such that TDS_sum = 0.73 * TDS_spece8 + 63, R^2 = 0.94. Does anyone know what's going on? Thanks, Herdis

Tom, thanks! I was away for a week and didn't see your answer until now. I won't have access to a computer running GWB until next week; I'll let you know if I have any further problems then. Thanks again, Herdis

Hi Tom, I tried to do as you described above and it worked, but only for the last speciation that spece8 performed. I loaded the scatter data set I have and none of the data plotted when I picked "system parameters" - "Carbonate alkalinity". To sum up, I use a script to speciate multiple water samples at the same time. In the script is a command that reports the result of each speciation to an output file which I later use as input to activity diagrams and various plots in Gtplot. I believe that in order to plot the Piper plot correctly, I have to have a column of carbonate alkalinity, as calculated by Spece8, in my scatter data file. I still haven't figured out how to report the results for the carbonate alkalinity from SpecE8 to the output file. I would greatly appreciate your help on the issue. Best, Herdis

Tom, thanks again for your input. No. I should probably specify again what I am trying to do: First I run SpecE8 with around 100 samples. The results for each sample are "exported" to an output file with the command "report", see this clip from the script I attached to the original post: if {[report success]} { puts $out_id \ "[report TDS]\t[report Carbonate alkalinity]\t[report activity Ca++]\t[report activity Mg++]\t[report activity Na+]\t[report activity K+]\t[report activity Cl-]\t[report activity SO4--]\t[report activity HCO3-]\t[report activity CO3--]\t[report activity SiO2(aq)]\t[report activity H+]\t[report gamma Ca++]\t[report gamma Mg++]\t[report gamma Na+]\t[report gamma K+]\t[report gamma Cl-]\t[report gamma SO4--]\t[report gamma HCO3-]\t[report gamma CO3--]\t[report gamma SiO2(aq)]\t[report gamma H+]\t[report SI Antigorite]\t[report SI Talc]\t[report SI Dolomite]\t[report SI Tremolite]\t[report SI Quartz]\t[report SI Chalcedony]\t[report SI Calcite]\t[report SI Chrysotile]\t[report SI SiO2(am)]\t[report SI Diopside]\t[report SI Enstatite]\t[report SI Wollastonite]\t[report SI Forsterite]" I then take this output file and use it to plot all kinds of stuff in Gtplot (and also for scatter data in Act2 and other programs). You see that I put in bold my attempt at exporting, or reporting, the carbonate alkalinity to the output file. This setup gives me an error message that the keyword is not recognized. I guess I could speciate each sample separately and copy and paste the calculated carbonate alkalinity into the output file, but that completely defeats the purpose of writing scripts for speciating many samples at once. If you download the script and input file I attached, run the script and then open the output file specified in the script, you'll see what I mean. I hope my question makes sense now, Herdis

Tom, thanks for the quick reply. I'm not sure I understand what you are saying - what values exactly do I put into the column with header "Carbonate alkalinity"? The carbonate alkalinity value calculated by specE8 (as reported in the generic output file generated by SpecE8 after each sample and then overwritten by every subsequent speciation) is different from all the values I have in the input file and I cannot see a term for exporting the "Carbonate alkalinity" in the list of reportable results on page 258 of the GWB 7.0 reference manual. I did experiment with running the file I attached here in SpecE8 and plotting it on a Piper plot and then loading the input file as scatter data to see if they would coincide and they did, but I don't know if that will always be the case. So, in short, seeing as the generic output from SpecE8 does include "Carbonate alkalinity", how do I explicitly export that value to the output file? And if I don't have to, why the clause on page 90 in GWB 7.0 Essentials Guide that one needs a column for "Carbonate alkalinity" to correctly plot "HCO3+CO3". Thanks again, Herdis

Dear all, I am plotting multiple data points in Gtplot 7.0 and one of the plots I use is a Piper plot, which has the variable "HCO3 + CO3". I just read that I need to have a column for carbonate alkalinity (as CaCO3 in units of mg/kg) in the scatter data file for this variable to be plotted correctly. My question is, how can I tell SpecE8 7.0 to report this variable? My current script is attached, so is an example from my input file. My input data for the SpecE8 multiple speciations contain both pH and HCO3-. The HCO3- concentration is not measured directly, I calculated it as the balance of negative and positive charges. On page 66 of the GWB 7.0 Essentials Guide, it says that "alkalinity" can be used to specify the composition of the initial system. There are two notes on this, one saying "Carbonate alkalinity, in mg/kg as CaCO3" and the other saying "Can be applied to constrain HCO3- only; pH must be set explicitly". I don't understand the second note and I certainly don't know if it pertains to the issue I'm asking for help here with. I just wonder if my input file, with its explicit values for both pH and HCO3-, is confusing the software. Thanks in advance for your help, Herdis HHS_example.sp8 HHS_example_input.txt

Tom, Thank you so much! The script runs perfectly and I'm glad it was just a question of coding. I better sit down with that tcl manual now Best, Herdis

Thassel, thanks for your help! I appreciate you taking the time to read my post and reply. So, I downloaded your input file and ran it with the slightly modified generic command script for spec8 and got a bunch of error messages. Most of them appear to be related to swapping, but I still got the ominous "Don't know keyword: T". I tried modifying the script so that swapping would take place but it didn't work, my guess is that I don't know scripting well enough to put the swap command in the right place. I did get it to work in the GUI, though, and the samples converged beautifully. Would you mind sending me a copy of the script you use to run the input file you attached? I'd love to try to run a script I know works for other users and see if it runs on mine. One thing I forgot to mention at the outset: I'm running GWB7.0 Thanks again, Herdis

Tom, Thanks for the quick reply. I've attached a sample input data file to run with any generic script in spec8. It'd be great if you could take a look for me! Best, Herdis Herdis_test_input_data.txt

I have a large number of sample analyses from hot springs, each with a different temperature (from 25°C to 98°C). I'd like to use spec8 to calculate the speciation etc. of these waters but I haven't had any success including the temperature in the data file that the software reads. The header is a problem, none of the headers "T", "T©" (this is supposed to be T(^C) without the ^...) or "temperature" are recognized (I get error messages saying "Don't know keyword xxx". When I run the samples individually in the command window or the GUI they run just fine but it'd take me forever to run all the samples that way. Does anyone know how to incorporate temperature in the input data files for spec8? Any help and suggestions are much appreciated! Thanks, Herdis