honestly bro, i can't really tell what the blotches are from the pics.
the yellowing looks like mag def. . . what kind of water are you running again? ph?
Nitrogen and Magnesium deficiencies get confused a lot. The best way to tell them apart is, nitrogen deficiency starts around the tips and works its way to the back of the leaves, where a magnesium deficiency will cover the entire outer part of the leave and make the entire leaves yellow leaving the veins to stay green.
you could have a deficiency from a couple things. could be nute lockout due to salt buildup, you can check your runoff ppm after you water to check for this, and a good flush (pref with final phase or clearex or something) would fix that. . . could be your pH is off. whats your pH? pH of runoff? when was the last time you calibrated? you could just need more, maybe add some cal-mag?
Magnesium is absorbed best in soil at a ph level of 6.5-9.1 . (Wouldn’t recommend having a ph of over 7.0 in soil) anything out of the ranges listed will contribute to a Magnesium deficiency.