Update-
Been super busy guys and will have time to catch up and digest all this great info this weekend.
I am a bit disappointed at this point as there seem to be some issues going on but just not sure what they might be and/or if there is even anything to be stressed about. Topside, to my untrained eye, everything looks fantastic. I've never had a plant frost up like this, could be a lot to do with genetics, but also could be that things are going very well. The roots look good although they are stained light brownish per recent photo, no slime whatsoever. Temps in the res holding steady at 67.4F. The ph has slowly drifted down since the res change on Wednesday, was 6.1 after res change, gradually going down to 4.9 by this morning. I thought my meter might be out of calibration so I calibrated it, no real improvement. For what it's worth, the meter is flashing that the ph probe needs maintenance. I gently cleaned it with a small brush and then re-calibrated with no change but I still get the maintenance code so it could just be my meter is not giving accurate readings.
I am going to keep an eye on things and when I get home from work tonight, if things keep drifting downward, my plan is to change out the res again and ph the water up to 8+ before I add any nutrients back in. I have watched the nutrients bring the initial ph down so perhaps I just need a bit more headroom in the ph to get me through to the finish line. I've got less than 4 weeks to go and the last week, if I am not mistaken, will be a nutrient free flush? My thoughts are that it may waste a bunch of nutes, but if I change things out more frequently maybe I can baby this girl to a decent harvest?
It may not be a good plan, but it's a plan A and a learning experience. I may need a plan B, C, D???