HELP, Yellow and gray spots developing on two week old seedling

Today I woke up to find this gray and yellow spotty stuff all over two of the bigger leaves on my two week old seedling. I thought it may be due to ventilation or lack there of so I stuck my fan closer to my plants in hopes of getting better air movement. I have no idea what this is and I'd like to figure it out soon. Any ideas guys?
I am growing with CFL's so I don't think I could be burning them...
Anyways any help would be massive

Here is a better photo. It's getting worse almost every time I go in there.
Did some research, maybe its a magnesium/calcium deficiency?

Should I pick up some Botanicare Cal-Mag Plus?

What type of soil are you using? How often are you watering? What is your waters Ph?

I'm using this STA GREEN stuff I had already at my house, and when I googled it, people said it was decent for cannabis. I water like every 4 days or so. Going to stop watering even that often since I have a little gnat issue right now. I need to go out and pick up a meter but I use tap water, and my other plants are as healthy as can be.


I recently re planted them, the stems were a little too stretched. Could I maybe had done something wrong?