Problem or not?

Hey everyone this is my first post on this forum and also my first grow. Im not sure if I having a problem with my plants or not and was hoping someone might be able to give me some insight.
Stats:
Strain-Pandora's Box
Techna Flora Nutes at 1/4-1/3 strength (Starter Kit)
6 Weeks old from time of sprout
90W LED light was 10" above plants but moved it up to 18" today
Temp.-73-81 degree
Humid.-30-45%
Homade C02 generator out of 2-liter bottle
Desk fan for air circulation
Aluminum foil tape covering just about everything
12 gal bubbler system with 2 6" airstones and a 55 gal air pump

Problem:
Two of the leaves on one of my plants have rolled up like burritos. I have read that this could be a Mag defiency but its only on one plant and they share the same Nute resevoir so I kind of ruled that out. I've also read that it could be heat or the light too close, which is why I moved mine up, but I have a LED which doesnt get hot at all so I dont think thats it either. Ive read as well that low humidity could cause this, and I'm thinking that might be it. Im goin to go by a little humidifier tonight, but was just wondering if anyone knows what this might be from. The rest of the leaves and the other plants leaves look extremely healthy. I just dont want to mess my first grow up so any insight would be greatly appreciated. I have included Pictures of everything.










My Setup
Burrito Leaf
Plant with the Burrito Leaf
Closest plant is curled leaf plant
This is the great looking one
also the healthy one
another shot of the healthy one

Yep, problem but I think you are right on track. I tried a small humidifier in a small space but got everything wet. I get a hand towel and hang it with the end in a bowl of water and put a small fan on it, the towel wicks up the water and the fam moves the air and I pick up 25% RH that way and its stable... gotta fill the bowl every couple days but worked better for me.

Not familiar with LED lighting but if that was HID I would say your lights are too close.

I ended up putting 4 TBS of epsom salt in my resevoir raised the lights and put a 30$ cool mist humidifier in there from Walmart. It's been about 12 hrs since all this and the leaf looks like its starting to uncurl just a little bit and the face is all wrinkly. Definitly looks like its dried out, its just weird that its only affecting one leaf. The humidity has been around 50% since I added the humidifier. I think Im going to go ahead and add another 4TBS of salt to my 12 gal resevoir, which makes 2/3 TBS per gal. I hope the problem goes away, my babys are about to enter the veg stage and I want them to be healthy.

You must have a pretty good air flow in there. Good to hear its working well.
I used the same thing and water was collecting on the walls and I was afraid I would short out my light.