No, I'm not sure about that because I not yet have ph meter ;( is there a way how to normalise soil ph?are you makin sure your pH isnt bouncing all over the place? looks kinda like ph flux issues
I have not yet used any nutrient mixturesLooks like severe nutrient burn... Give her a good flush and time to recover
Now upper leaves are getting yellow too and some even get dry what that mean?You are over watering. I live in the desert southwest (Arizona USA) and i only water once a week. Give them a good soak...with runoff...I check during the week by pushing a finger carefully into the soil. when leaves at the bottom yellow up it's usually too much water and when the leaves at the top yellow up it's because there isn't enough water. Plus a leaf will look wilty when it is in need of water.