Can't seem to diagnose

Hey guys, I've been reading all over this website and many others and I can't seem to figure out what my problem is with my plants.
I'm running them in coco/perlite mix, and give them GH nutrients every other watering. I have them under a 600w mh light that is about 15" from them. It stays about 70-80 degrees in my grow room.
Can someone help me diagnose them? I'm at a loss.

Try backing up your light. & go easywith the water & nutes. Other people know alot more than i. Guess its late

are you letting the coco dry out some? looks like over water.

2 pics look like wind damage ?

I had just watered them, but sometimes I do think I get a little excited and water too much haha. But I do have an Oscillating fan sitting kind of close to the plants. I'll try moving that around and see if it gets any better

Every time you water in coco it should be a nutrient solution. Never water coco with plain water while the plants are growing. Always pH the solution to 5.8. The life of plants in coco is totally pH dependent, just as in deep water culture. Use reverse osmosis water if at all possible. 16" for a 600 mh is too close isn't it? U keep the back of your hand on your plants for a full minute without any discomfort at all?? Doesn't seem possible at 16". MH bulbs give off more heat than hps. How big of a pot u planted in? Is it fabric?

Oh I had heard to alternate waterings. As for the PH I keep it a little under 6( I use the drop color test.) and ya I can keep my hand there for a minute, I have that oscillating fan under there, it keeps it like 75 degrees directly under the light. Could it just be wind burn? They're in 7 gallon fabric pots

Here is the nutrient schedule I'm following.

just an update, i moved the light up about 6" and changed the fan so its not blowing directly on the plants and they are already looking better.

Oh good! Live & learn these guys know a lot on here! Totally helpful! Off to iditarod last day. Have a good one!