Update On Closet Grow (Pics)

Not a real lot going on atm. mostly the plants are recovering very well. throwing some pictures up get some of your guys thoughts.
Notice some of the leaves are starten to show strange discoloring in the middle of the leaf.
In the last picture two of the newer leaves are turning almost black and getting hard.
My biggest and healthiest plant only is growing fan leaves atm? none of the branchs that come off in the middle er what not are really growing

on a side note. i ordered a 6inch fan to going into that bathroom fan to try to vent out alittle better. then i wil be adding a DIY filter onto that.
I still need to figure out abetter way to get some induction. only options are going threw the door.
Its a hallow door. so what i did was cut the middle section of the bottom 2x3 out so it was open to the hallow section. then 1/3 the way up the door on the inside i cut a hole on and put a dry vent cover over with a fan attached blowing in. but it doesnt seem to be working out

my first post the pictures didnt seem to work so here they are.

anyone know what could be causeing the problems with the leaves?

There all in Mirical Grow Organic besides 1. Other 1 is MG Potting soil 30% perlite.(Attempting at LST)
going on 6 weeks old.
just added a few lights so there under 16x cfl's 100 equivalent
Lights are abit high atm. i just rigged up there hanger. and i cant lower it anymore my fan is hitting

it looks like water stress. Either too much water or too little water.

Stick your index finger into the soil down two knuckles and if its moist at all, then don't water for at least another day. Take multiple days in between watering. Paying too close of attention to your plants is also possible, so just water them when two knuckles down it's dry or at least very close to that.

oh and could be PH from the Miracle Grow. MG is notorious for having too low of a PH from way too many nutes.

Nutrient lockout occurs at extreme PH's (like <5.5 or >8.5)

must not be waterning them enough i guess. because im only watering 4-5 days now. i got amoisture meter at around the 2week mark and sense then been going by that to tell if there dry or not. and i tend to let thm dry out abit because i did have the habbit of over watering when they where babys but sense then they have turnerd right around.

Yeah im thinking its a PH problem. idk how to fix that