Plants showing discoloration plz help

So me n meh GF are trying to establish a makeshift grow from a couple bag seeds and I built a lil' grow box with what we had around the house: reflector, a 35w n 2 20w CFLs, a lil cardboard box, aluminum foil, a old PC power supply n 2 PC case fans. The rig stays from 70-73 degrees, 20% humidity, and has constant airflow. We put the seedlings in some organic potting soil my GF had for some lettuce n other veggies from the summer. We are willing to upgrade pretty much everything but I think mainly I need to transplant to some better soil/potting mix and get some better light(s). Any suggestions would be verrrrry much appreciated, just tryin to save our babies.

Issues:
Plant 1 (NYC Diesel/pic 1 and taller of the 2)-Bottom set of leaves started discoloring showing dark blotches and the upper leaves have starting turning a lime greenish color starting from the center(stem) and moving outward and have been drooping. Also, the new growth is showing darkening on the leaf tips.

Plant 2 (Strain Unknown/pic 2 and shorter of the 2)-The bottom set of leaves is showing discoloration in form of light spots appearing only on the tips while the upper leaves seem to droop a little.

Hopefully I figured out how to add pics and they are attached...

Do those cups have drain holes cut in the bottom? I had curled down leaves so I cut back watering and they got nice, long and straight.

Does that soil have nutes in it? Guano? Burnt tips could be nute burn, but those baby leaves (round ones) will normally wilt away. Have you yet checked the PH or flushed, sooner or later you will. I'm just throwing ideas out there, lots of variables could effect things.

Keep those small lights close, but not too hot either. Sounds like a fun little set up. Enjoy!

humidity is alot lower then i like it to. dont want it to get under 40% for seeds and veg room i like to keep it 55%-60%

We do have drainage holes in the cups and they seem to drain fine. I figured overwatering was the issue initially but then the color change to light green on the upper leaves started to occur and there hasn't been any change since we cut back on watering. I have been meaning to pick up some pH test stuff just haven't gotten around to it and I tried to check the balance on the soil but couldn't find any info on the bag. Also, have not bought or used any nutes yet, was waiting to see how the soil worked out. Starting to think the soil was depleted of nutrients from sitting outside for too long before we used it for mj.

12 hours of light per day and cool temps~mimick spring time= better chance for girls

higher temps and longer light hours= boys

no nutes for 30 days....put a sprinkle...like a pinch of epsom salt and that will green your plants up...but wait at least a week and let them develop more leaves before adding anything

I'm to the point I think its gotta be a nute issue (or lack thereof) in the soil so I'm gonna try n transplant into some FF Ocean Forest with like 30% perlite in the next couple days n see if that perks em back up cause plant 2 has in the last 24 hours began to show the exact same symptoms as plant 1. Only problem being im pretty much broke till payday on fri.