leaves are yellowing curling up and turning brown!!! HELP!!!

My babies are not looking as good as I think they should. I just moved them from florescent light to a 250 w mh they are about 5-6 weeks no fert but the leaves are a bit yellow and curling and getting a bit brown. I have been spraying once or twice a day only watering when I think they need it. The light is about 18 to 20 inches above with a small fan temp is about a constant 80. humidity is a bit low and PH is at 7. Any clues to what is happening? I could realy use some advice.

My guess would be it's time to feed them,for what it's worth,I grow hydro.

My friend says that I burned them with the light. I dont think so. They should thrive in this new light!!

Ph has to be 6.5 .

Yup feed them. The dark splotches look like phosphorous deficiency. The yellow orange leaves could be zinc deficiency.

Hit them with 1/4 to 1/2 strength nutes depending on NPK of your ferts.

5 - 6 weeks is a long time to vedge without nutes