Basically the exact same set up I have, and using the same brand nutes as my first indoor grow. At least with hydro it should not be a watering issue (2x45min floods a light schedule) Are they clones or seed? And how old? they look quite young-could be unfurling. Sometimes, when clones make the transition into vegging, the original leaves look a bit sad and odd. This is normal. In any event, GH nutes are a bit strong, so try dropping the PPM by 20% and do not worry, they will most likely come good- if you are uncertain of the nutes try flushing with luke-warm water, and then go onto a one shot hydro feed like Formulex -VERY easy to use, I use it for cloning and early growth before I tent them. I use GH Floragro, Floramicro and Florabloom in combination from then on as recommended by GH (go to their site, and download the pdf chart they offer, it's good). I do mix them about 10-20% weaker because the FAQ part of this and other sites say more plants are damaged by over-feeding than under feeding. My grow went fine and is smoking lovely, after a couple of Fatherly panics. I am currently using tomato feed instead of Formulex (MUCH cheaper) for vegging and will use my (expensive) GH stuff when 2 weeks into flower. Do not worry-it will be fine.
happy new year