Is this wind burn or something else?

[420_Noob]

Good morning everyone!

I previously had a small, non-moving fan blowing on the bottom of my plants, and I started noticing what you see in the attached pic.

I am wondering if I caused wind burn on my plant, but can't quite determine if what I am seeing matches online pics of wind burn.

My setup is a simple insipid grow tent with a small hydro set up. Ph is sitting around 6.2, and I have been using Technaflora as my nutes, and following their feeding schedule

Any ideas would be greatly appreciated!

[420_Noob]

After some more reading. This looks more like drastic PH changes early in the plant life. It seems my PH tester was almost 1 shui point out of calibration. After recovering it, I have the PG balanced @ 6 right now. Hopefully this solves the issue.