I've spent hundreds in chlorine just so far this year and I'm at my wit's end. My pool looks beautiful - it's clear straight to the bottom (30K gallon inground vinyl liner). But I cannot get a chlorine reading. The pool store doesn't seem to be steering me right. Usually I don't even need them - I adjust everything myself and it goes fine. I just dumped about 8 pounds of dichlor into it and I'm still getting NOTHING on my reading!
My results from the pool store this morning were .5 available chlorine, 3.8 total chlorine 156 alk (high) 7.5 Ph (okay) 62 cyanuric acid (high).

All else okay.
No clue what to do. I can't even get it to a 1 for chlorine let alone shock level of 10!

What am I doing wrong? I've been doing this for 10 years - I can't afford to buy any more shock. They gave me Yellow X this last time to try to boost the chlorine but it was 20 bucks flushed because it's done nothing.
Why does my pool look great but no amount of shock will give me even a small reading? I even dunked my test strip into some chlorine in a bucket to be sure the "purple" was working............................?