White spots on lower leaves

I am growing this Trainwreck in an indoor tent. She is currently on day 3 of flowering. I started about 10 days ago on the FF nutes. I have been watering every 3 days with distilled water. I noticed this white powdery looking stuff on some of the bottom leaves. It does not rub off and it is only on a few of the bottom leaves. Is this something to worry about? Should I cut those leaves off? Thanks a lot for reading.

Powdery mold spray 5:1 skim milk - water