and the moral of the story is; Start small!
Seven grand worth of equipment tells me your trying to setup at least a 4000 watt growroom. (if your not then your doing something horribly wrong because I could setup a 8000 watt grow for that price knowing what i know now)
by the looks of it you havent even grown anything under a 400w lamp.
trust me theres HUUUUUUGe differences between a 400w grow and a 4000 watt grow. , the 4kw grow being exponentially harder by about 10x. 10x the variables 10x the light 10x the heat, 10x the plants to worry about, 10x the work.... and 10x as much to fuck up. 10x as much electricity. you get the picture.
you have to think of growing kind of like conducting a symphony or an orchestra... It doesn't just all fall into place automatically. You have to practice.
And its not the best idea to start to practice conducting an orchestra during the biggest performance of your entire career. Most successful conductors start out with bagseed and a compact florescent.
My first impression; if you wanna do hydro ditch the soilless mix crap and start them in rockwool and transplant to hydroton. I'm willing to bet your plants are overwatered. or of course... if your feeding them nutrients at this stage
they're toasted by nutrients for sure. they dont need any nutrients until their first little leaves start to turn brown. and start them on 1/4 strength reccomended (this is after about 3 weeks of growth)