What this video covers
Most dehumidifiers are running at the wrong setpoint, and the clip gives the range worth targeting.
Between 45 and 50 percent relative humidity is low enough to stop mold establishing. Going lower is not better. Below 40 percent you start creating separate problems, including dry skin, irritated airways and timber that shrinks and cracks.
The takeaway
There is a band rather than a lower-is-better rule. Set it into the mid forties and leave it, instead of chasing the lowest number the unit will display.
Read the full written guide: Dehumidifier Settings for Mold Prevention.