Amy,

You're going to need to get a K2006 or K2006C for me to continue helping you . . . AND you're going to have to stay out of that pool store. They are not only selling you products you don't need, they are giving you bogus test results: there are NO dealer test systems that would allow them to distinguish Alk=151 from Alk=160, much less from Alk=155. Those systems usually are based on electronic readers of 'goofy strips' -- but the strips themselves can't reliably measure Alk well, much less CYA.

Meanwhile, run your pump / filter 24/7 and add small doses of bleach to maintain your chlorine levels.