1st try hydro(DWC)

My first go at hydro. Using an Elite800 air pump w/ small airstone at the bottom of a 3G reservior. 18/6 photoperiod. Fox Farm 6-4-4 Grow Big, 2tsp/G. Using pH meter for a pool, only goes to 6.8 so that's where I keep it. Buffer pH w/ Nitric Acid. Only 13 days in.
Pic @ 13days:
https://www.rollitup.org/members/jrogers141210-albums-bagseed-ish-picture3799-13-days-dwc.jpg
not sure if there's anything wrong at this point, had to remove the two lower sets of branches due to bugs.
BTW I'm kinda learning what works so I only have one plant as to not direct too much energy in the wrong direction.
anyone have some advice for me?

14th day, newest, top-most leaves started bending away from the light troughout the day. Raised light to approx. 17.5" away from top, I'll check to see if problem persist tomorrow. She is looking very healthy but has problems with pests such as flies and small sucking insects, anyone have some insight as how to get rid of these annoyances eh?