text: I find it depends on the scent, I made one for my mother in law nearly 2 years ago and it’s still going!! And smells amazing, but then I’ve had one that I made and it lasted about 3 months?!? Different scents same % same reeds etc, but normally my customers come back twice a year for refills, that’s 20% mix with thin reeds 6 or 7 of, if I use the thicker reeds then I use 4