Grey patches on fan leaves

Greetings again, my youngest plant is showing some strange spotting on the lower fan leaves. Ive looked all over the internet and cant find anything matching my problem, I did just transplant into a larger pot a few days ago and damaged some of the roots....guys take a look and see what you think the problem is....

looks fine too me..maybe a bit of nute burn starting...but i'm not positive...but ya it does look healthy. what lights you using?...nutes?...any ventilation?...PH?...etc..etc..etc.

Does it rub off, could be powdery mildew

Im using 2 cool CFLs, venting every 3 hours for 15 min. I only give nutes once a week at about 1/3 strength. water every 3 or 4 days. temps at 70, light 24/7 the plant with the issues is about 3 weeks old. I know it should have more light, but right now im putting all my lights towards myoldest plant, which im trying to get to show sex. (Its been 3 weeks and still waiting...) anyways, I think Ive determined that the damaged roots may have caused it because it hasent gotten worse as of now, and the plant is still growing.