Spots on leafs > 2nd week Flowering

Hello,

I'm in my 2nd week of flowering.. and I have noticed some random yellow spots showing up mainly on the lower leaves of my plants. Seems to really only be affecting 1 of my 3 plants. The other 2 do not nearly have as much.

Note** about 2-3 weeks into Veg. I had nute burn affecting all 3 plants. Is it possible that this is just spill over from then?

All 3 plants seem healthy, and growing about 1 inch every 2 days or so.

feminized White Widow seeds
400 Watt HPS light - approx~ 8 inches from the tops
circulating air
ppm is approx ~ 200
PH 5.6-5.8
Waterfarm hydro buckets

See pics of affected plant - you can also read my Grow Journal ( https://www.rollitup.org/grow-journals/168292-white-widow-closet-grow-hydro.html ) if you want a history of the plants

On a side note.... I bought feminized seeds, but if any of these pics look like they could be males please let me know! I havn't started sexing yet, but i'm assuming feminized seeds will yield female plants

Thank You!!

im pretty sure in the flowering stage this is quite natural. im pretty sure its because light is working harder to get to the bottom leaves of the plants. if this is not the problem slightly add some N to your little girls and it might turn around the plants color

thank you for the advice!
So I should expect the other plants to show some spotting on the lower leaves as they mature. It would make sense, since not all the light can reach those leafs.