[steve the plumb]

I have the stockman pipes.It does make the overflow a little louder because of the water sloshing but its not that bad.The stockman pipes are pretty quiet.It does make a differance in sound but compared to not having the stockman pipes its a joke.When I didn't have the pipes it was a waterfall.Plus at night the unit shuts off so you won't hear it.Like I said its not as quiet but I wouldn't say its loud.You just hear a little bit of sloshing.My fans for the lights are louder than that.Its not annoying,trust me if it was annoying I would notice.I am very happy with the unit and I don't know if having a center overflow makes it more silent.I can't tell you its dead silent because its not.The tunze pump makes a slight humming sound but I heard it does this when the pump is new.I don't have a decibel meter to tell you exactly how loud it is.I would get yourself a unit and if you are not happy with it sell it or return it.Like I said off e bay I saved $100 compared to every where else.