discolored/brown leaf tips, small brown spots

Not sure of the strand but could the discoloration be some kind of deficiency? Right now I'm only giving the plants a veg solution. Watered once a day, they receive about a 1/3 cup of water/veg plant food per plant, per day. Grow box their in has two T5 grow lights, temp sits at 75F with 50% humid. The plans are a month old.

everything has to be perfect in rockwool or your plants will suffer. It looks like too much nitrogen. but who knows it could be ph related or lockout also. I would put them in soil as soon as possible. They will thank you later.