Wow, I'm pretty shocked nobody gave you the right answer.
There's no need, or use for molasses until mid/late flower, but it is contributing to your problem.
6.2 is WAY too low for FF. Your PH has locked out most necessary micro, and macro nutrients. You want to feed around 6.8 in soil. It's early enough to save em, but you need to act quick.
There's enough nutrients in FF for about 3 weeks.
Take out a cup of soil from 1 of your containers, and run 7.0 water until you get enough run off to test the ph. Post your results.
Start feeding plain water at 7.0, and within a week they'll begin getting healthy again.
Keeping the lights too close is NOT, and very rarely a problem in veg, unless your lights are burning the plants.
The only real good advice I've read was stop using molasses. Molasses with drop your PH. Also keep your water temps between 65-70 when feeding.
If you have any questions, feel free. I've been doing this a long time
The white spots are probably nothing, but if you got them from clone from a friend, or dispensary, who knows. It's worth grabbing a scope, and taking a look.