Yellow @ Green interleaving on top leaves

Hydro running aggressive H&G nutes.
4 weeks into flower
Hydroton
PH range 5.6 to 6.2
Tap Water

So a few days ago I noticed that on (1 of 2) of my Blue Dream Haze's girls the upper leaves were showing signs of yellow interleaving. First I was thinking Mag or Iron issue, but why on only (1) plant? I have (4) total, the other (2) are Betsy. So why only one showing the signs on a hydo system, they all get the same nutes. PH was high for a couple of days, so I was thinking lockout.

Tonight I noticed that the other Blue Dream is getting it also, but only the leaves near the other Blue Dream that had it first. Stepped back, hit the pipe, thought about it, then noticed that there was a path of yellow starting at one spot on BDH1 then going back across to BDH2. Now I am thinking environmental issue.

Grabbed the light meter and noticed that the strength of the light from my 1kw HPS bulb was much stronger along that path. So maybe some sort of light reflection issue from a smudge, handprint, etc on the hood or bulb.

Question.. Can light penetration be to strong? Not a heat issue, but more of a bleaching effect on the leaves?

Any other thoughts?

No thoughts huh.. Bummer was hoping someone would have an idea or confirm what I was thinking.

It seems to be getting better so either it was PH lockout or adjusting the light helped..

looks like nitrogen difficeincy. do double ph test and add light supplement.

also you leaves look a bit ridgy (alligater skin) usually cuased by overwatering, which would screw up you nute intake

Hmm that never crossed my mind, the over watering. Hydro system feeding into buckets 4 times a day, ebb and flow did not seem like alot to me.

It's the light ... mine are doing this now