I found brew friend water calc. I am making a west coast ipa and it seems my water needs a bit of sodium, a bit of mag, and some calcium for bitterness.
My plan is to add 12 g gypsum to 7.3 g boil, 5g kosher salt, and 6g of Epsom for Mg.
This will give me Ca around 120, Mg 20, sodium 76...