The Sulphur Vapouriser will keep 100m² of growing area healthy. The sulphur is not burnt so the nasty smells of sulphur oxides are not produced. The Hotbox Sulfume keeps the sulphur at the exact temperature necessary for vapourising the sulphur but not burning it. Harmless to plants. Shut off fans and tape up all leaks in flooring, doors and windows. In bad infestations can be used for up to 12 hours a night.