Weve done the same with our two...let it run all night. On the weird chance the power goes out or flickers and the machines we ue turn off, we have to run in and turn them on or they wake up. DD is 5 and shes had hers every night since day one...same with DS. Me and DH use an app on his phone. I just cant sleep in a perfectly silent room, and I think it helps block out any weird noise they might hear while you and dh are up. Annnnnnddd.....from a totally lazy perspective, it sounds like more work than its worth, turning it on and off. Is there any reason why DH wants to turn them off?