Quote Originally Posted by atkinson40 View Post
What's up with my pool supply store who gave me a 400 CYA reading?
Once people get their K-2006, more often then not they discover that their pool store's testing was bogus. What people don't realize is that pool stores have a NEGATIVE incentive to provide accurate testing, because ACCURATE testing reduces chemical sales!

=> With at 36K pool at pH less than 7.0, start with 2 boxes (added slowly to the skimmer, pump on), wait 4 hours, and retest.

=> You really, really want to avoid zero chlorine.