2 weeks flowring why brown tips?

Is this normal for tips already turning colors its only been 2 weeks flowering.could cfl lights be to close....can hairs get nutrient burn?

What have you been feeding them, and how much runoff is coming out the bottom? It looks like a nute lock out to me..IMO...I would flush with half strenght nutes if it were me....flush= 3x the amount of the pot size...3 gal pot = 9 gal flush ....and so on...good luck and welcome to RIU