Balancing pH, KH, and GH in a beginner tank

I'm looking into getting a shrimp tank. The water where I live is extremely hard, with a 240+ mg/l KH, a 180+ mg/l GH, and a natural pH of 8.5 or above. I've been able to lower the pH slightly (to 8.0) in my 20 gal snail tank using a small piece of driftwood, but I can't bring it down anymore for the health of my snails, so I'm getting a second tank to curate an environment specifically for shrimp.

I need to figure out how to balance all three. I've heard you need some KH and GH for shrimp health, but not too much, and that you can lower KH and GH with certain types of substrate. However, I've also heard that those substrates can lower pH too much.

How do I balance all three? What do some of your setups look like? What substrates would be good to use to naturally maintain water conditions? I don't super want to keep buying distilled water to artificially lower KH every water change.