Crystal Air ozone generators reduce or eliminate the ability for the exposed mold, mildew and fungus to grow. Mold and mildew grow in dark and humid places where there is a lack of oxygen. In all cases the moisture and humidity in the walls, floor etc., must be removed permanently to effectively eliminate the problem odor. Once moisture is removed, all visible mold and mildew should be removed, then a shock treatment procedure can be preformed lasting for 24-72 hrs. A small ozone generator can be used to help control continuous mildew problem odors if they persist.