Yellow leaves along the edge

Hello rollitup so I am running a 4 plant 600watt hps right now my plants are growing and looking to good yesturday I had to cut two males (( but Im running a 3x6x8 weird ass closet I know lol but on about 2 of the plants it is getting yellow along the edges not like the whole leaf which I think means nutrient deficiency if I am not mistaken so my question is what does it mean when its just yellow on the edges I have attached some pictures too assist you with what I am trying to say 1st indoor grow btw...

Take a look here...http://www.growweedeasy.com/nitrogen-deficiency-cannabis

Ahhh I dont think its nitrogen because its leaves on top as well, and the its not the whole leaf turning yellow only the edges of the leaf as seen in my pictures but I could be wrong but they been like that for several days and I assume the whole leaf would be yellow by now which is not

Try giving some calmag pics are blurry but it kinda looks like begining of magnesium def. Looks also that the leaves are a little heat stressed just bye the curling upwards of the leaves but the pics are a little too blurry ha ha

What's the temp near the tops of your plants? What is your soil mix? How far is your light from tops?

The tops are about 85-90 varies and I have fox farm ocean forest, miracle gro organic soil and some shroom compost in there and I am gunna say about 20 inches from tops