Cant Figure it Out?

I'm thinking its some type of deficiency but not sure.

Plant are 4 weeks old tomorrow (Friday)
Growing in soil with Schultz plant feed at only 1/4 dose, and only fed twice.
CFLs
Grow cab is about 3ft L x 2ft H x 2 ft W
I have intake and outtake fans, with temps around 84 at the highest.

What kind of soil?? Oh and don't use plant food/nutes that you can buy from WalMart. Shultz is like a 10-15-10

Forgot what the name of the soil is. Not MG, some plain potting soil with no additives

and Schultz isnt that bad. I havn't had any noticeable nute burn or any other problems from it.

dont feed for a week see what happens

Well, since u have some off brand soil, and you are using Shultz plant fertilizer. Those leaves sure looked nuked to me man. How can u say its not nute burn when the edges of your leaves look cooked. The problem with using a plant food from Safeway or something is that even if it was a deficiency how would you know and fix it because your only using 1 type of like fertilizer. and you have no other type of necessary nutrient to fix the problem. So there would be no possible way to fix it, because your only using water and Shultz.

Example -
Calcium Def - Use Shultz
Magnesium Def - Use Shultz
Nitrogen Def - Use Shultz

.........do you kinda get where i'm going with this man. Not trying to be a dick, but man u gotta lay off the Safeway brand fertlizer and soils. Invest in some good stuff!! I promise it will help you.

Oh, and if a product has the words All-Purpose Plant Food or All-Purpose Fertilizer. Don't buy it!! A big red flag should pop up when u see those kinda items. Yes, u could possibly grow some sort of bud, with those kinda products, but dude it'll prolly be crap. I'm just saying.

I'm gonna say magnesium. Put a teaspoon of epsom salts in a gallon of water next watering, and don't feed. Do it again if you need to. You probably won't. And it's ok to use the ferts you have, so long as you're going easy on them. It's a weed. I used miracle grow and shit was fine. Love ya.

@thewake, already been doing that with no difference really
@ MrGreen, I'm working on getting better nutes. And yeah what you said makes sense.
@stoney, I'll try the the epsom

So if I were to go to my local garden/hydro (more garden) store, what type of new nutes should I look into getting. Not necessaraly name brands, but what range of NPK and such