tiny white spots and brown area (pictures attached)

This is my first grow, though I have grown vegetables etc. They are 20 days from beginning germination, They are blackjack feminized seeds. Currently under 4, 4ft, T5 florescent bulbs. The lights are running 24 on to stabilize temperature. I transplanted 1 week ago to 1 gallon pots. Top 24% is light warrior (LW), next 50% LW and Ocean Forest (OF) Mixed 50-50 and bottom 25% OF with a couple tablespoons of blood meal. No nutes have been used. 1 plant had the tiny white spots develop 2 days ago and developed the brown area today, another has a few white spots develop today. There are two more that show no problems yet and are not pictured. I see no mites an do recognize them from outside gardening.
I hope to keep this organic as possible. Any suggestion would be appreciated.

55 views and no one commenting. How about some help here.

Looks like the same problem as youngbud510 I have never seen this problem before so can't recommend anything.

look on the bottom side of the leaf , lots of lil white spots? mite infested?

I've checked for mites. there are none. I'm familiar with mites and aphids from vegetable gardening and feel fairly confident there are none but thanks for the input.

if you get ferts on the leaves wile watering it will burn them

I've used no fertilizer at all. Just a palm full blood meal divided among the 4 in the bottom 1/3 of the pot.

even water drops can magnify light and cause burns

any changes?

they actually look good other than 1 big brown spot an a few tiny white spots. They are continuing to grow. So it may be nothing, I hope so.

Yeah, I'd say let 'em go for a bit. I can't really see the white spots in the pics, and the patch doesn't look to bad yet. Keep and eye on them, but don't harass them to much.

i'm veggin a blackjack right no and it's tall as hell and really healthy looking. unfortunately it's my ony one and it might be a male. oh well... good luck.

I bought 5 feminized Blackjack seeds, only two grew and the plants were struggling. I began to see the same spots on the sun leaves(the big leaves). As the plants recovered and stabilized, the top leaves are green and beautiful. It is a shame to not have the lower part of the plants producing, hopefully the healthy parts will flower nicely. I feel the spots were caused by stress on the plants when they sprouted. I bought the 5 seeds from Nirvana Seeds. I corresponded with them about all five not sprouting and sent pictures of the ones that did and they sent me 5 more feminized Blackjack seeds for free. I am no longer concerned with those spots. Maybe your plants are stressed by something in your set up.