First grow in coco, wondering if this could be nutrient burn

[KidGrower]

This is my first indoor and coco coir grow and have been feeding the plants an EC of 1.6 for a couple days until runoff until i started to notice the discoloration on new growth tips. Yesterday i gave her just Ph'd water of 5.9 to try and flush the medium to see what my runoff was reading and it was right around an EC of 1.0-1.1. Im wondering what could be causeing the discoloration and then burning on new growth tips.

 

[Imzzaudae]

Looks like your E.C is on spec. How far are the tops from the light ?
Should be way up top 30" about 60% power.

 

[KidGrower]

Looks like your E.C is on spec. How far are the tops from the light ?
Should be way up top 30" about 60% power.

Its about 40 inches away i have other plants in there and thats why its far away. Ive been running 75% intensity because there is a older plant in there that likes the higher intensity , im at day 29 of veg and want to get them to 45 before i flip so i want to make sure i have no nute burn or deficiency's before i flip.