The next step in analyzing your local data is to graph
the trends of NH4+, NO3+, and SO42- and compare them
with the pH trend. Using the same scale for all three
ions will allow you to directly compare their relative
amounts and see how they change over time.
Examine the range of your data values for all three
of the ions to set the upper and lower limits of your
scale, then create an appropriate scale on the left
side of the graph. Graph the three lines for your NH4+, NO3+, and SO42- data.
your cursor over the graph to view an example of the
pH trend over the same time period. As the pH scale
has a very different range of values, it is shown on
the right side of the graph.