HELP! WIlting plant-rdwc

Any Pic's? Sounds more likely a ph issues cause even
an over/under feeding isn't going to kill the plant instantly?

ph is dead on, there's a gaurdian on the reservoir. I think I may have it figured out. I may have had the water level a tad higher than normal,...if the rockwool stayed soaked,....could that bring rot into the pic? I just stripped all the rockwool from the roots (yup, some brown chunks in there), letting it sit with naked roots right now to air out a bit (lower roots are still in water)

This why yo need a pic or two. Ya the rock wool has too dry out depending on how big
is yo rock wool. I seen it where it don't dry out around the main stem and it just rots
right around the stem. If the rock wool is bigger yo git root rot if it don't dry out~
yo leaves drooping too from over watering? Didn't think yo should leaves the roots
in the water~

The rockwool is gone now. If I take it out of the water, it will die, this is a hydro set up

keeping the base of the stem wet is probably the #1 killer of pot plants, once the main stem rots the plant is toast. If you have drip emitters set them to 15 min on 45 minutes off with a timer. If you are using dwc then only fill the water line to an inch or so below the net pots. And you can certainly add more fertilizer if you have foot tall plants and are only running 400ppm. you can safely double that in my opinion, but I don't think that is what killed them, stem rot did.

also, make sure you have fans running so that it dries up water before it can damage anything.