OK, got the res changed out.
Still dealing with my contaminated RO tank from all the construction. I need to drain it and refill it and see if the problem goes away now that I'm all finished with the remodel, sitting at about 115 ppm out of the barrel. I also forgot to pump clean water through the chiller to get all that nutrient water out, ended up with a base ppm of about 150 before adding anything.
With all that in mind, I went ahead and built the res finally resting @ ~800 ppm. That gets me to about 650 of actual nutes, gonna watch close. I had been running at 600 ppm but starting to see a very small bit of possible PK deficiency on a few of the fans so I thought I would raise that slightly and see how she does. Hoping to have the ratios squared away at this point but really flying by the seat of my pants here, just learning and if I make mistakes, it's a learning experience and I will get better.
Got a couple of photos of the roots while I had everything drained. I thought they looked great.