I have been using wet towels hanging in the tent to keep the humidity up in the tent while waiting to see if the old seeds in the soil end up germinating, I can get the humidity up to 75% with the wet towels, otherwise it is just over 40%. Maybe there will be times when I won't need the humidifier throughout the year, but I remember reading 70 to 75% gerrminating/new seedling and dropping by 5% a week down to something like 50-60% during veg, and then 40-45% during flower. I can imagine that once I get something to grow I will eventually need a dehumidifier due to keep the levels right, but it's the opposite at the moment.