I'll get some pics here in about an hour. I'm sure it powdery mildew but I'll put up pics anyway.

It's interesting I've only seen it on 4 of my plants, all the rest are fine, are super green with no mildew(all but 4 are the same strain). The 4 plants I keep finding it on are yellow, however even when I do find the mildew it's not very bad at all, and it only covers maybe 5 leaves per plant.

It was definitely caused by poor ventilation, I was keeping my room sealed with a really small fan blowing fresh air in, lesson learned, however since I've added waaaaay more fresh air into the room I've not noticed the mildew as much. I also think the spray is working very well. My Humidity never gets over 50 and my temps hover around 75-85(gets to 85 when I turn on CO2)