Tips of 1st leaves turning black-ish brown

My plants are 2 1/2 in. from lights. I have two 150 watt CFL's. Havent started nutrients yet or checked pH. Why are the margins of the leaves turning black-ish brown? Should I start nutrients?

i have the same problem..the first set of leaves are yellowing..light green color..with some brown

dude I got i dont water let is dry for days they will kick back

wait what???