Really impressive grow man....I know this post is a little old but I was hoping to get the same question answered as skewb...what was your watering cycle all through the process? I'm using an almost identical setup and would sooner adopt a tried and true method of watering than experiment with what I have.
Also, what kind of nutes did you use? I'm currently using the 3-part nute program from Advanced Nutrients. I've heard you're supposed to be gentle with nutrient in drip systems.
I have my pump on for an hour off for an hour while the lights are on alternating. i use fox farms and keep ppms around 700-1000 depending on the strain