Thanks Doc,

This am I did add unfortunately already additional Soda Ash (5.5lbs) to increase the PH.
My readings in the late afternoon are (I will verify my future ColorQ readings with my OTO test kit):

Pool has vinyl Liner:

My 5/31 (6 hours after soda ash addition)

FC 1.99
PH 7.6
TA 249
CH 189
CYA 3
Total Chlorine 5.27

Just Added this evening 5 Gallons of Liquid Chlorine, brushed and will repeat as instructed (and hope to see dead algae soon). Will do some reading on the other points.

Thanks for the advise.

Ernst