It is very important to use all the sticks or vine reeds supplied with the chosen fragrance. It is recommended not to use fewer sticks than are supplied. On first use it is necessary to let the sticks or reeds soak for an hour and then turn them over. To adjust the intensity of the home fragrance, all or part of the sticks/reeds provided must be turned one or more times a day. The sticks that accompany each diffuser are designed to keep the color of the fragrance stable. Therefore black stick.