Plant immobile element deficiencies are noticeable first on younger tissue. Calcium and boron are always plant immobile nutrients. Sulfur, chloride, copper, zinc, manganese, iron and molybdenum are intermediate in plant mobility
B/c you are showing signs of def. in your older leaves (closer to the apical meristem), it is the above elements that are not getting to your plant. This means you need to feed your plant with these nutrients.
Also, lower your pH, 5.8-6.2, from what ive read is the IDEAL pH that plants can uptake nutrients.
You see, these elements are in the chemicals you have been feeding your plant. Also, your soil pH is a big thing. Do you have a soil ph test kit or electronic? Without knowing the pH of your soil, its impossible for anyone to tell you what exactly is wrong. If your soil pH is really alkaline you need to add lower pH h20 such as 5.8 pH... if really acidic add higher pH water.