Dan, have you considered taking out the spray manifold and going straight DWC? It wouldn't be that hard to do, and might boost your growth.
I've noticed this plant can handle a lot of stress pretty well. Like I said earlier, it was down to a pint of nutes and still going strong. I've also drastically changed nutrient doses several times, such as going from full strength to double, bouncing from a grow mix to bloom and back, and the damn thing hasn't even flinched. I don't check my ph at all. I mix a new batch, top off after a few days, and at the end of the week start over. After this competition is over I'm going to see how hard I can push this plant. I'm thinking about abrupt light cycle changes, withholding nutrients, extreme temps, anything else I can do to piss it off, because so far I haven't been able to.