Quiet/loud is an opinion. I just put by 3k in yesterday, I would call it loud, but only because everything else in my system is totally silent. I have a 75 and was told it couldn't be silent. It is silent. With that in mind, I hear a whine when it is going through it cycles. If it was a consistent hum it wouldn't be so bad. It is more of a inconsistent whine and then it stops, then you hear it, then you don't, then you wonder what that noise is, then you realize, then you are annoyed for a while, then you forget about it, then you start wondering if you hear something again, then realize what it is and . . . . . . . I never expect this to have any noise at all. Heck, I didn't even research it. Now not sure what to do. Not sure if LFS will take it back. I am looking for totally silent. If a little noise from a pump or water falling doesn't bother you, this won't bother you. If you want silent, you will be disappointed.