Could you give us some more information? Most of the time it's impossible to tell you exactly what is wrong with just a picture of the plant.
Ppm 1598 .... spider farm lights sp2000 and sp1000 and a 100 Watt blurble light
@Ace kush How often do you water? Kind of looks like beginning signs of overwatering.
Soil or Coco? If coco what nutrients are you using? How old are the plants? How far away is the light? I prob wont be the one to provide ya with an answer, but these are the things ppl need to know to help ya out. Good luck man