Humidity

IMO, if you have proper temp, light, circulation, and watering technique, humidity takes a backseat, as far as "do or die". Once your seedling is out of that first 1-2 week period, humidity is secondary and beyond. For example, in mid winter, with ambient humidity at 20%, because of house heating, my veg grows were in the 30-40% at best. Maybe for better base growth, humidity would help, but I have always been happy with my results. FYI, my outdoor grow (diary) right now, is experiencing less than 20% humidity. Just keeping them watered, is good enough for them to be healthy.

Hi there! The humidity is really important thing in plant growth and actually it is the vpd thts important (Humidity/tempo ratio). But you can and many does grow great buds without ever paying attention to the humidity. You just need to adapt whatever you have and do accordingly. Like if you have really high humidity the plants wont drink so much and dry air they drink more so it affects the strenght of your nute solution for example. And too much hujidity can promote mold but with proper airflow etc this should not be a problem. So to answer your question, no it is not do or die kinda thing but helps a lot