Hard to say if it was the fed or not, i have been feeding mine 400ppm@ph6.0 until i turned the res on my auto pot on and i filled the res with 550ppm@ph6.0 and she seems to be okay with it. maybe damping off, lack of 02? or maybe its the lights? just spitballing blind here bud, i hope they wake up tomorrow and snap out of it.