Hi Katelyn,
Thank you for your response. Now I am able to plot all my samples. I had another question regarding Piper plots.
If I want to replace bicarbonate with nitrate (since I have very little bicarb and nitrate is a major anion in my samples). Is there a way to switch the apexes in the piper plot? Or if I just simply put the concentration of nitrate in the bicarbonate (in GSS), would that be just as accurate? I am concerned that the program may take into account (or change the concentrations) when it plots HCO3 + H.
Thanks again,
Alison