watsup fellow blades? iv encountered a problem... ive been out of town for 2 weeks and left my neighbor in charge of my watering, i pre mixed everything of course to make things as simple as possible.. but anyways i come home and my plants looked great EXCEPT for what i think is nute burn, some leaves on SOME plants have gotten a bit crispy and almost grayish in color.. mind you these plants are 4 weeks old.. please tell me what you think

the strain is grapefruit kush, its in the new Roots Organics "707 Formula" ive been watering with bat guana, 3d organics "3rd eye", and advanced nutrients sensi grow A & B.... i think ive covered anything, im not sure though im pretty blazed off some blackberry kush
ps sorry for the shitty pics