So, I'm at the counter, 2nd in line waiting to pick up some liquid Cl at Leslie's...
Guy in front of me is getting his water tested - and standing there with a 10lb pail of Stabilizer.
Clerk finishes the test, and sells him an additional 5 lbs and says, "Protects your pool from UV rays, you should get another 5 lbs... And add it every year."
Guy says, "do I need any acid?" - Pool Clerk, "No."
Guy pays and leaves - and leaves his test results behind on the counter. When the Clerk went to the back to get my Cl, I looked at the guys results:
CYA - did not measure.
pH - 8.0
dKh - (IIRC) ~300.
It took every thing I had in me not to say anything to the clerk (or go run out to the parking lot to grab the guy that's going to have pool problems for the next 5 months, and again next year).