1st time grow...spots/holes on leaves...bugs or deficiency?

Hey GrassCity! New to the forum and new to growing. We have only had one issue thus far and we can't seem to figure out what is going on. So here's the details...then take a look at the photos and give us any insight you may have.
Started the plants from seed on May 23rd-ish. Started them in germination station and then moved into the CoCo in our Rainforest 66 Hydro system...it's RDWC. They are all growing strong aside from one runt. We are running two strains...Strawberry Banana and Jack 47 (very similar flowering times) and the little one is a Jack 47....The PPM is a constant at 1400 which is right where we want it for this week, and the week prior it was steady at about 1260. The PH is also just fine at 6ish.
The lighting is a 1200 Watt LED ViparSpectra and it is a very safe distance away. We even tried raising it up when we noticed spots on the leaves thinking it may be from the lights but thus far we have ruled that out. We will be adding one additional 1200 watt in the coming week.
We use Fox Farms (except SledgeHammer). Followed all the measurements to a T. We are supplementing with Dyna-Grow and Cal-Mag when the PPM or PH needs a quick adjustment.
We had what seemed to be an infestation of these tiny little gnats but when we did our flush and nute change this week, we seem to have eliminated the gnats.
The leaves that are affected are the lower ones (the ones closest to or sometimes even touching the CoCo). It started as small brown spots and sometimes led to small holes in the leaves as well. The first photo is the worst leaf...and its only that one leaf on that plant. It doesn't seem to be affecting the growth at all. They are still going strong. We have noticed that the leaves towards the bottom are a deep dark green where the new growth is a lighter more greeny green for lack of better words. Would this suggest a deficiency?
With all the variables and possibilities, it's hard for us to determine what the problem could be so we are hoping that someone else has had the issue and can offer some advice.

 

Yes they get sprayed with water on a regular schedule

 

The LED lighting combined with my cell phone camera does some weird things to the pics. The green looks normal in person. Just a noticeable difference in color from top to bottom.

 

Huh...really? I wonder why that is? The pH is right around 6

 

Ok...we will give that a shot! Thank you. The reason for the water spray in the morning was b/c at night we are misting them lightly with FlowerKiss mixture from FoxFarms that is supposed to help them out via top feeding and I was worried that if any was left over on the leaves in the morning when lights kicked back on that we would end up burning the leaves from the left over nutes and lights, so I was hoping the fresh water mist in the AM would eliminate that but turns out I was the problem huh? Lol We will let you know results.

Do you recommend removing the affected leaves?