I’ve had this for about a year and it still works great. Yes, you need to clean the reservoir to ensure the diffuser portion continues to work well, as with any diffuser. Some previous reviews are misleading, as I think the operators did not fully ready the instructions for use. 1) Yes, you can set the ambient sounds as your alarm (no need to hear the standard
alarm sound!). It is a little tricky to figure out, but just follow the steps in the instructions and you’ll get there. 2) Yes, you can adjust the alarm volume. 3) The alarm is easy to set to on, or turn off. I use it M-F and turn it off on the weekends. 4) I agree with the previous reviewer who mentioned the high pitch humming when playing sound and the clock light is dimmed. Because of this, it is “almost” perfect. I just end up turning off the clock light completely if I will fall asleep to music/sound. 5) Everyone in my house is jealous I have such a cool diffuser. I’m purchasing one for my mom and one for my son :)