OK, so as to further pursue the pH matter....

cheap electronic pH meters are usually not very reliable, and
+/- 0.1 units precision would be desired. I think going the
electronic meter route will run you 100 USD plus pH standards.

On the other hand, there are some narrow range pH papers that
I would think should work, but have no knowledge of people using,
owing mainly to my lack of gardening experience. This is not
same as litmus paper. Anyone know about the use of these?

What about specific flower petals? Some of these should work
well.... I think?

Also, I am curious about documentation on hot to properly measure
soil pH. I have run tap water over a pot of soil until it
leaks out the bottom, and then measured pH in the flow-through.
I reckoned maybe this is the water that is actually available to
the roots. This is convenient to use with standard lab pH meter,
but I could guess that botanists have some formal protocols they
follow. Any ideas?

Dominic-Luc Webb