Where is your humidifier situated? In the tent? In the lung room? Unless the air you're brining into the room is as humid as your humidifier is trying to make it, it will always be on. I am constantly exchanging air as such I'm at the mercy of the weather for humidity control. Between the hard water stains on my plants and it never shutting off, I got rid of my humidifier, and I just foliar spray when it's too dry.