I noticed some yellowish powder on the lower leaves of one of my plants today. Curious if its pollen or some sort of disease. I didnt get a picture of the powder but below are pictures of the 2 girls. 1200watt LED, 50/50 FFOF and FFHF. 70 degrees lights off and 81 lights on. Humidity between 40 and 60 percent. And 6 inch exhaust. Currently week 4 of flower.