it can be a whole lot of things. if the rest of the plant is fine, you can probably just pull them off. but it can be nuteburn, not enough light, disease, nute deficiency, etc. how's the rest of you plant doing?
Possible mag deficiency. Could just be burnt as well, if youre using calmag you can prob rule mag deficiency. If not you might want to go out and grab some. Also pics would make this a lot easier.
the rest is looking pretty healthy . Im not using nutes by the way . & i have two fluorescent lights about an inch from the top of my pant . Oh and using reguar dirt from outside .
yeah man it could literally be a ton of things. If you have a hydro store near you id recommend going out and grabbing a bottle of cheap veg nutes. I mean even if that doesn't solve this problem its only going to help your plant in the long run.
you should probably start by getting some good potting soil from home depot or something. vegging npk (Nitrogen, Potassium, Phosphate) ratio should be something like 20-5-5. also, what wattage are the lights?
well, that looks like something more than just nitrogen def. with the soil you have it in, there could be any number of nute/pest problems. its so young, just start over after visiting home depot or worms way. not to be discouraging, its just probably bagseed so its not a big deal. happy growing!