Soakin is right on.
I will add that I only check my levels on the weekend. I know just how much sanitizer to add during the week, so I don't check Alk or PH till the weekend, unless if I add water, I'll check then. My water out of the hose is around 7.0 and almost no alkalinity so if I suspect those values are low, I'll go ahead and check everything at the same time.