It was 7.6. I checked each time before treatment. I would see a starting ph of 7.4 - 7.6 and after treatment around 6.8. All treatments were done in the evening between 5 and 7pm. I only found one dead CC (1 pound) the day after a treatment and it may have been a casualty of a heron because it had a hole in it's lower side. Note: I'm using spa test strips for my ph and alk tests.