Yeah the water chemistry is different from region to region, some places have a drastic difference city to city.
There are a bunch of different options you could use to raise the kH and gH of your tank, usually these come in the form of powdered minerals or liquid buffers. Once you get those two to the level you want them, then your pH will usually stabilize itself.
As for your shrimp question:
I keep CRS in pH: 6.1–6.5, kH: 0–2, gH: 4–6 TDS: 100–180, Temp: 69-74F
and RCS in pH: 6.4–7.4, kH: 2–5, gH: 6–8 TDS: 150–250, Temp: 69-74F
As you can probably guess from the difference in the two species, Crystals are more demanding in terms of water chemistry. Cherries will adapt to most ranges, but prefer the water to be slightly harder.