Can anyone tell me the deficiency here? PPM Question also.

Im using General Hydroponics Expert Line along with protek, hygrozyme, and cal-mag (botanicare). This feeding I used organicide (5ml per gallon) my PH was 6.4/5, my ppms were pretty high 1150 ish . . . im growing in straight pro-mix. (plants are 8 weeks old, started counting weeks after new growth on clones started.) I do have one question when it comes to monitoring ppm also, im using a blue lab meter and it has a ppm500 setting and ppm750 i believe, Which one do most people look at when they discuss their ppms.

Its not on all the leaves or all the plants, just a few.

Im just rambling here lol . . . . could it be a burn from spraying neem oil on the leaves?

did you have the lights on? it looks maybe like too much light or some sort of blight disease. just take it off and dont worry about it. always defoliate the bottom 3-5" of ur plants to avoid mold