Luftfeuchtigkeit

anything above 65% is greater risk... the 'right' rh depends on temperature, too. The resulting VPD is something to consider. There are VPD tables you can image search for and reference. Atmosphere temps are -2C warmer than the leaf surface temperature. If you don't have a infrared thermometer to take leaf temp, that's good enough... these numbers are grey areas. exhausting to a different area that doesn't 'feed' the intake to the tent can help, as long as ambient RH% is not high. Otherwise, you need a dehumidifier. Canopy size is part of the equation too. Smaller canopy = less transpiration and less moisture released into air. if they are not fully grown, this will only get worse, so if you need a dehumidifier, sooner is better.