Preface: I am a new pool owner as of 2/19/16. We purchased a home with a small pool (app 8,500 gallons). I'm a DIY, so I purchased a 6 way HTH test kit at WM. Since then, I've also taken samples to a pool store in town. Two recent analysis:
CYA 151/ 151
FC 15/ 10.7
pH <6.6/ 6.8
Alk 10/ 104
CH 127/ 402
I added 2 lbs of soda ash yesterday to attempt to raise pH to 7.2
On 4/28, it was recommended that I stop using any form of chlorine, drain off some water and add Balance Pak 100 6lbs (now I know that I was sold very expensive baking soda). I tested pH with the kit (I plan to purchase a better one on internet) and got the same reading of 6.8. My question is why the big upward swing in CH and what to do about it, if anything?