My tap water going into my ro
filter has a ph of around 8.2 it comes out of the filter at around 7.0 so ro
lowers the ph.
When your well water has a lot of minerals in it its ph buffered which is why you say that the ph chemicals wont touch it, they will work eventually but with unknown results if you keep adding stuff to lower the ph it will eventualy overcome the waters natural buffers and then crash to a very low ph, so there isn't much you can do safely going the chemical route with your water.
When you get everything out of the water through filtration the water will have a neutral ph which is a ph of 7.0