Serenade is a beneficial that kills harmful fungi. It is Bacillus subtilis.
Treat your plants with a light mist of that; you don't need a lot as it is a living thing and will multiply on its own through cell division.
Keep a steady breeze on your plants and dehumidify your grow area as much as possible.
If the night temps are quite low, add a small space heater to bring them up, which actually reduces your %RH and prevents dewfall, which leads to more fungus.
Never smoke moldy buds, especially if you have any immune or respiratory issues, especially mold allergies!