Afghan Kush x Black Domina

Sooo.... The last week was a bit of a pain in the ass. I flushed the plant on day 14 and just gave the plant plain water for the remainder of week 3 in flower. By about day 18 I started to notice that the leaves were getting a little yellow on the top of my mother plant. The LED lights were only 7 inches from the canopy! I hadn't been paying attention to how much the plant had grown and how close it was to the light. I raised the lights so they are 14 inches above the canopy. I thought that would make the color of the leaves return. However, her condition started to get worse. Several of the fan leaves on the top of the plant started to curl up and fold like tacos. I also noticed that some of the top fan leaves were getting copper colored tops and edges. some of the lower leaves under the canopy began to fall off with severe deformities and grey patches. Some research into the matter led me to believe that I had nutrient deficiencies. I knew that I had not fed her nutes in almost a week but I don't think that would lead to the plant's current condition as quickly as it did. I then tested the Ph runoff from the pot and it was incredibly acidic! Almost 5.0! My crap Ph pen had crapped out and was giving erroneous readings. I have since flushed the plant again and properly Ph'd the water. Now I have to wait and see if her condition improves. I hope this doesn't affect the yield too much. Pro Tip: Always calibrate your meters before use!