Water Hardness

My tap water report shows that there's a hardness of 192 as CaCO3 and a TDS of 460. Will my tap water lockout magnesium?

Nah, that's a lot of calcium though so you gotta balance it with your fertilizers.

How much epsom salts would that take? Also, what's a good organic way to raise the pH of said epsom salt solution?

Epson Salts is Ionic and rises the PH, I'd use 1 tbs per gallon and get fertilizers low on Ca-Mg like General Hydroponics.