Not sure what problem is

[Kiracho]

This is my first ever grow and things have been going great so far a few issues here and there but the growth has been awesome I'm loving the learning experience. However I've noticed some changes in the leaves on all of my plants in the past couple days I'm really not sure what the issue is I had a magnesium deficiency at one point and fixed that but that was the only issue.

I'm growing in hydro with an LED a 2k vivosun at a distance of 26 inches. they caught up to the lights and I just raised them they were only 18 inches away I messed up and didn't keep on the lights as well as I should have.
PH is 5.5
I'm also following the GH Trio recommended dosage of 5ml of each per gallon along with the recommended calmag supplement.

The plants are 27 days old from surfacing 30 days old from germ.

Any help would be much appreciated!

(the bright yellow is from the lights and my camera, but you can still kinda see what I'm talking about)

One more thing to add these are GDP I'm not sure if that matters but I figure I'd add all the info I have on them.

 

[3Dino]

Only like giving advice in person this is my 45th year growing cannabis. But I will say the plants seem like they have a slight nutrient in balance and personally I would keep the room a bit cooler at night

 

[3Dino]

Kinda as in this idea

 

[Kiracho]

Yeah my issue is i have no idea what nutrient it might be. They are still steadily growing and have shown no sign of stopping but as a first timer everything freaks me out lol. Also temps are around 77 at day ans 70-72 at night.

 

[Kiracho]

Think I may have found the culprit. My PH was 5.2 a tad bit low.

 

[ComfortablyNumb]

5.2 could do that. 5.5 is your optimum.
Does your light have a dimmer? I would lower it maybe 5% or 10% to reduce stress on the plant.

 

[Kiracho]

Yeah the lights have a dimmer on it I'll try that out for sure if this PH change doesn't help them out. These pics however were right before I raised the lights about 8 inches and since then they didn't seem to show heat stress just the deficiency. I appreciate the responses though! This has been a really great experience so far.