?Light Green/Yellowish Pokadots on Fan Leaves?

My friend has a hydroponic system installed because she uses marijuana medicinally, and she has been having a strange issue with one of her plants which is in the system, although there are six other plants which have remained unaffected. The plant is developing these light green/yellowish dots all over the two lowest fan leaves only, and they don't appear to be killing or severely damaging the plant. Anyways, she brought her camera over and uploaded a couple pictures of the situation to see if any of you happen to know what is possibly going on and what possible solutions would be for the scenario.
Thanks rollitup.org!

Are you serious? Not a single person on here knows what this problem could be? And I thought this was a forum for experienced hydroponics growers. . .