Plants are 3 weeks into flower and I’m about done trying to treat my PM problem by spraying different liquids all over everything and it’s not working anyways. I know UVC light can be used to kill PM, but at what concentration? Will a 3 watt handheld UVC light work to get rid of this? How should I be exposing my plants to this sort of light in order to kill the PM without damaging the plants? Please help! Thanks!!