Having had made about every mistake in the book there is to make, I think I recognize a couple of things from your pictures. First, how often are you watering? They look like they might be drowning to me. Are you letting them dry out completely before hitting them with water? Remember that these are weeds, and they actually thrive if you torture them a little in this regard. Definitely get that ph meter too, and keep the ingoing water between 6.8-6.3.

Second, there seems to be quite a distance between nodes on your plants, indicating a lot of stretching, so your friend definitely had the lights too far away. Get your lights right down on them, no further than 4" away.

Lastly, forget nutes. You are in miracle grow, which already has the little nute balls in it. Anything extra until mid flower is likely to kill your baby off.