Two Week Old Baby...Need nutes yet

I just started growing and am planning on growing three plants in hydro and three in dirt. have transplanted one seedling into homemade hydro drip in 3 gall bucket. 2 gl res (hydroton). The leaves are burning on that one but I had my drip working overtime so I think it might just be a little root rot. now its running three times a day 4 15min we'll see. I have only planted one in the dirt and it is doing much better, only three weeks old and already has its third set of leaves at 1.5 in. using 400 mh in center of grow room 6*9*8. temp is 77day 69nt. 36% humidity and fan blowing 18hrs a day w/ lights. should I have the fan running all the time? when should I start feeding the ones in dirt thier nutes? should I/could I feed them hydo nutes. All I have right now is some tea, hydro nutes-ionic grow and pure blend pro grow. I have orchid 20-20-20 as well for the other plants in my turrarium. wll that work for my plants in dirt. thanks a bunch. also have some other questions on lighting but not sure if the room won't be to hot if I get another converable HP/MH light.