Get an OTO -- yellow drops -- test kit, and test with that, if you don't have a K-2006. Do NOT use a DPD color match kit to test when you are adding large amounts of chlorine! If your 12.5% was fresh, you added about 25 ppm of chlorine to your pool . . . which is MORE than enough to bleach out a DPD tablet. Also, your pH test will NOT be reliable when you are adding those sorts of chlorine doses.

I do not understand how you went from CYA=45ppm on May 16, and CYA<10 ppm today. I'm kinda at a loss -- either your test kits are wacko OR you are using strips OR you've added a bunch of water (as in, drained and refilled) or you made some serious errors in your earlier testing.

May 15 <===> May 24
Chlorine 11 <===> Chlorine 0
Ph 7.2 <===> Ph 8.0
Alk 80 <===> Alk 220
Cya ~45 <===> Cya <10

Basically, you've given us results from two completely different pools. I'm hoping you can shed some light on this, because we can't offer any advice, based on these completely contradictory results.