G13 Cinderella 99 - 2 ES 300's in a 4x4

Looks almost like a calcium and magnesium deficiency, possibly excess potassium, or ph issues. I would start by checking the ph of your runoff next time you water your plants. If it is out of the optimal range that could be causing a nutrient lockout. If that is the case then I would flush the medium with properly phed water until the runoff is reading within the optimal range. This will get your ph back to good and open up the absorption of the nutrients it was previously locked out of. But like i said it could also be an excess of potassium if your nutes happen to be high in it. That would also be helped with a flush to clear out the built-up nutes.