What R the Basics (ha ha) of water pH

I am just starting out AG and have been reading all I can about water pH, and tyring to apply that to brewing with better water. What I have learned is to get your towns water report and to test your water before you brew, and to adjust based on the beer style. Treat your strike and sparge water? How do you know how low to go since the grain will reduce it further (since its hard to test pH color in a liquid with suspended solids)? I guess I need to know the basics please. Any input would be appreciated.

I'd start by reading the chapter in John Palmer's online book, "How To Brew", on Understanding Mash pH. It is better to adjust the mash, not the strike or sparge water.