Thanks again all.

I've been testing CL levels at least 2 times a day to understand what is happening. The run down of the last 20 hours or so is this. Weather is Sunny and warm.

Last night added the extra bleach suggested by Watermom. I was at 11.05 plus another bottle which should have taken me to around 14.5. Checked this morning before work (left pool open overnight) and measured around 14. Covered the pool for the day, came home and measured again (about 11 hours) and got a 12.5. Kids swam, dog swam, I swam (2.5 hours passed, I checked CL again and measured 8.5. Added 2.84 gal 6% and leaving open overnight. Will measure before I go to bed later and expect a 14.5 to 15 reading. Will check again in the morning. My money says it will be in range of 13 to 13.5 then when I get home am expecting around 11.

Will keep you posted.