Return pump for overflow

Kind of...lol...it sounds like a bathtub is continuously draining. But I'm used to it now and don't even hear it anymore. And to me, it's not a bothersome noise - it's kind of relaxing.

 

Oh I know the sound. lol. I have a single overflow running currently on my old aquarium. I had to put some airline tubing down the drain to stop the slurping sounds. Now just sounds like some running water.

 

drain silencers
http://www.3reef.com/forums/general-reef-topics/overflow-silencer-quick-question-86048.html#post863723

http://www.3reef.com/forums/i-made/herbie-overflow-video-79073.html

 

Mine was kind of loud until I did some tweaking of the ball valves on my overflow and return lines. You can tweak them until a perfect balance is acheived and this will usually cut down on a lot of the noise.