Sulphur is a highly effective fungicide. It works by preventing fungal spores from germinating, so it is best used as a preventative because it is less effective once a mold has taken hold. It also acts as a powerful pest deterrent. By using a Sulphur Vaporiser during the dark cycle when the extraction is off, you will help prevent powdery mildew and other molds. A sulphur vaporiser is an invaluable addition to any hydroponic grow-room. Use in conjuction with a silicon additive as part of your feeing regime to make the cell walls of your plants more resistant to mold attacks.