Drooping and and discoloration.

I'm growing dwc for the first time. Plants have been doing well until about the 4th week or so. I'm not running any nuits so it's either a deficiency or over watering. Im using the root spa 8 bucket system with 1000 watt led. Water is purified 0 ppm at about 75. My ph was off for a little while but have corrected it with no signs of the plants getting better. Any help would be much appreciated. Thanks for looking.

youre not feeding it??? that could be the cause of your problem... it looks like it needs some N and food dude. you may be able to pull through and get some new growth but i think this grow is done brother sorry. i mean you MIGHT be able to get her going again and it not be a waste of time and money but your odds are not looking good

What is your rez temp? I'd guess maybe too warm and not holding O2. Roots healthy and white?