Some leaves on couple of girls are starting to yel...

@CuzDAmato I beleive it could even be calcium deficient Ive had a few plants that looked similiar that turned out to be calcium related hollow stems is a giveaway , check one and see.

Nitrogen deficiency does look like this. At this stage in soil you could have a ph issue though. Your nutes look complete, the amount seems high. But I only use liquid nutes, so 22ml per litre might be ok. Too much nutes can change ph, either directly, or via soil microbial waste. Once ph is too high, it doesn’t matter what you fed them, the nutes become “locked out”. Fix ph first then look at nutrient deficiency.

Yes the yellowing is from a nitrogen deficiency. Cannabis still needs nitrogen in flower just mid way through you lower dose. Bugs get some neem oil spray when lights go out so you don't burn leaves. Brown spotting is a calcium defeciency. If your using heavily filtered water you probably need to be adding cal mag back.