Humidity is not to be looked over! It determines your plants resilience against mold/mildew in addition to how much your plants need to drink. Getting it just right can drastically improve plant growth and increase your yields!
Young plants (from seedling to end of vegetation) love high humidity levels, they should be kept around 40-60% RH, as far as 70% for clones and cuttings. If you see wet spots forming on the leaves, humidity is too high or you need to increase air circulation
Ideally, the relative humidity of your grow room should be lowered to around 40-50% at the beginning of the flowering stage. Lower levels of humidity in late flowering will cause some plants to produce more resin, this may also cause some