I have an Aqueon Quiet Flow, Tetra Whisper 40, and a Aquaclear50. All of them are quiet. The Whisper was noisy when I first got it and I had to replace the impeller. Now it is very quiet. I never hear it unless something gets stuck. My Aquaclear got a little noisy a few months ago and I found a broken impeller. I replaced that and it went back to being quiet. If the filter you were given has been sitting around for awhile, it may need cleaned and a new impeller. You can take it apart and clean the motor with q tips. You can replace the impeller for around $8. Most of the time that will fix it.