Some Leaf Discoloration

[Agemon]

I've got some issues going on with one of my plants.

Strain - 818 Headband
Hybrid 60/40
40 days into flower
Indoor grow
Medium is soil, I'm using Happy Frog, 15 gallon container
1245 watts of LED Power, 2x 600 LED, and one 45 watt LED
I have a dedicated A/C unit, tent stays between 74-80 degrees
RH is around 40%
Last check soil PH was about 6.45
There is a trace of WPM here and there. I use Serenade at the first sign of WPM, I found 2 leaves with WPM tonight, they were plucked immediately. Then I sprayed with Serenade.
I flush/ feed every four days. She dries out pretty quick, I modified the container she's in, I put lotsa drainage holes in.
I use General Hydroponics Flora Nova Bloom and there associated nute line.
My grow room is 4x2x5, I've got two small clip fans at either far side or the tent blowing in toward each other and an exhaust fan that pulls 190 cfm. The exhaust is running 100%, 100% of the time.

Here's a picture of the plant.

Here's a picture of the problem.

I'm not sure if this is sulfur deficiency or something else, it's not rampant, but there are a few leaves here and there. I've got around 23 days left until harvest.

I just don't wanna see all my effort go downhill, thanks in advance for any help you can provide!

 

[Bloodguy]

The only time my leaves did that was when I moved them from a poorly lit closet to direct sunlight. I hope you can crack this case. I'm gonna stick around and see if I can learn something tok.

 

[Agemon]

The only time my leaves did that was when I moved them from a poorly lit closet to direct sunlight. I hope you can crack this case. I'm gonna stick around and see if I can learn something tok.

That seems to be the feedback im getting. I was looking at the two leaves on the left. Theres a continuation line between the light spots.

 

[AnimaSola]

If it's sulphur then there might be purple streaks on the stems. A handful or two of garden gypsum sprinkled on your soil will add calcium and sulphur without changing your pH.