Older leaves with yellow veins and general light green color that then turns yellow with blotches.

[elcoloan]

Hello friends

In a plant I have flowering, last week I noticed bottom/older leaves yellowing and getting brown spots/blotches after yellowing, then crinkling and falling with just light touch. I started monitoring other older/bottom leaves that were still green and now notice they start from dark green, then turn to a lighter green... and before passing from light green to yellow, they begin with the veins turning yellow and then the rest of the leaf starts getting yellow and blotches and spots appear, then it falls off easily.

What is this symptom of? Not too worried about it but I am curious... maybe N def? Ca def? both? other?
I tried searching on online but i couldn't find a single picture or description that matched this... maybe hammerd veins from atypical Ca def symptoms would be the closest i found... but I suck and web searching, so I do apologize if the answer was obvious and i didn't find it myself.

It is a photo plant in its day 26 of 12/12, under a QB style lamp pulling 60 Watts from the wall... the light is at 12 inches from canopy.
The plant is in a supersoil that is supposed to only need water. I've been giving tap water about every 3rd or 4th day, at 0.1-0.16 EC, and ph 6.5-7.0. About every 7 or 15 days i give some EWC leachate (2-2-2 npk) in the water at very low doses (total EC is never over 0.6). Temps are between 20-25C / and RH is between 50-65%. Runoff comes out at 6.5-6.8, and EC of runofff is always between 1.4 and 1.6.

Here are two pics to give you a better idea of the plant:

How it begins... notice the yellow veins, light green interveinal, and a blotch starting to appear:

After a day or two:

Any input is received and appreciated.

 

[LittleMT]

Plant looks nice to me, older, yellowing, dying leaves when the plant is in flower is normal. The tops appear very healthy..... As she continues to bloom expect more lower leaves to yellow.... I would let them be, as she is doing what she does...... Nice plant.

 

[elcoloan]

Plant looks nice to me, older, yellowing, dying leaves when the plant is in flower is normal. The tops appear very healthy..... As she continues to bloom expect more lower leaves to yellow.... I would let them be, as she is doing what she does...... Nice plant.

Thanks for the input and nice comments! I'm not really worried by the symptoms... I did assume it is normal considering the stage of the plant and that I don't really add many nutes with the waterings... but in past grows the yellowing would happen a little different. I've never had yellow veins like this... i've had all uniform yellowing or intervenal yellowing, but this is new for me so I am curious.