Adjust the intensity:
To adjust the intensity of the scent, turn all or only some of the provided sticks, once or several times per day.

Verify the duration:

The duration of a fragrance depends on the size of the area in which it is located, its temperature, out of direct sunlight and drafts that can accelerate the evaporation. However, there are a few tricks to make the fragrance last longer:

When purchasing the diffuser, always match a refill of the same fragrance to use in small quantities, but more frequently. In this way you will be able to keep the level of the fragrance always on top of the curve, avoiding that the quantity of oxygen inside the bottle affects on the evaporation
Keep the fragrance out of heat sources
Combine to the area you wish to scent the right size of the bottle.