...And I'm probably changing my tank water
too much too often anyhow, going at 50% a week, trying to reduce algae. I
could use some advice from someone who understands hard well water.

I'm no expert but I'm in a similar situation - well water with high pH and
immeasurable kH. Do not change too much water - you CAN do too many water
changes. I know that's counter to what you usually hear from the experts,
but they all have city water, the swine! Your established tank environment
modifies your water to suit the needs of it's inhabitants as closely as
possible. Doing massive water changes is destabilizing. I try not to do
more than 10% - 20% weekly, depending on the tank.

kush