Im Out of Ideas

I have no idea whats up wtih these plants about 6 out of 20 plants show this stuff on the leaves and i cant find a pest for the life of me except for the seldom little black fly and i never see them on the plants i use a 30x triplet earlier in the grow they were innoculated with rasta bobs and the other day were sprayed with neem oil any suggestions

Looks like a lack of nitrogen, is it mostly bottom leaves?

Minor PH problem, not to worry if it isn't getting worse.

i run the ph at around 6.2 or 6.3 and they are getting plenty of nitrogen yeah bottom leaves for most part i just put air cooled reflectors in because i thought maybe the heat was doing it they were at around 95 yesterday

My first though was heat. But neem will burn leaves why are you spraying neem? Its looks like a burn of sorts. But i dont know much

i've also notice little white dots on some of the leaves, with no sign of mites or white flies, but i do have fungus gnats.

I'm not sure can you post a few more pic's?

the white specks are a lil saw dust hehe had to do some immediate exhaust construction but i figured out my damn brand new hanna ph meter is off by almost 2 i cant belive they arent worse!

btw i am growing og bubblegum, violator kush, tangerine dream, cheese quake, NL, and bc purple