Not to add to your confusion, but with metals in your water, I would try to keep your pH toward the lower end of the "good" range....I keep the pH between 7.2 and 7.4 in my pool because of the iron in my fill water.

And yes, they will tell you to add all sorts of chemicals to your pool at the pool store because they are in the business of selling chemicals. I just tell them that I have it at home, thank you very much.