Any chance?

The staining of the roots could also possibly be down to the nutrients u are using, I had the same issue and decided to change my base nutrients which were by plant magic to base nutrients by a company called Grow dog. 👍🏼

Roots just look stained. Make sure you ph your water at 5.8 for veg, check everyday. Feed chart for photos. Day their born, 400 ppm, 0.8 ec. See good growth that week up to 500 ppm, 1.0 ec. Next week and you see good growth, 600ppm 1.2ec Every week you increase 100 ppm if your seeing good growth. If your not seeing good growth then stay with that amount an extra week. Stop increasing when hit 800 ppm, 1.6 ec. Only give more if you see they really need it. Keep your water cool with frozen pop bottles all in and around the rez. Hydroponics recovers or goes bad very quickly. Keep parameters in order and they will recover rather quickly. If their autos start at 200 ppm from sprout and work your way to 600 to 650 ppm.