Roots are fine. NPK RAW Grow nutes turn the water brown, thus staining the roots. This is a simple 4 stone bubble system. Below the black tray are 2 more holes into which I swap out frozen bottles of iceHello.
I hope it's the lighting or the coco but your roots look brown. Not the health white I like to see. I like your ingenuity but without a chiller rdwc is hard.