Root Rot?

Flood table using Coco. Plants were looking killer a few days ago and then all of a sudden they looks like this with drooping leaves and yellowing, dying leaves...It seems to be getting worse too. I hit them with some hydroguard. Should I do a full rez change?

If it's root rot you can see the signs on the outer most roots there is generally a smell also but of course it won't over power the smell of those buds. I would say that isn't a sign of root rot it looks like something is being left behind in abundance, uptake problems and it looks like pH problems but you didn't mention that. You have the course of action correct do a reservoir change then protect your investment with hydroguard for peace of mind. Anyway my money is on them making it to harvest on time still with a rez change.

Thanks. ph is 5.6

have you checked your ppm/ec? when they're consuming a lot of nutes it changes the balance in your res quickly, or so i've been told.