Herbi overflow making noise

[Palmer]

Thanks for the replies everyone. I had a bit of an "Ah Hah" moment since I have set this up wrong. I didn't understand the Herbie overflow system and just continued with what I thought was on the tank prior to my getting it. I do not have any valve on the main pipe return so no wonder I am getting noise! When seeing this system for the first time I thought the only advantage to it is the second pipe as a contingency if the first gets clogged. I didn't understand the silencing aspect of controlling the return flow from the first pipe.

So I did go out today and get a 2 " ball valve to install tommorow on the main return pipe to the sump. Based on fkshiu's comments this isn't optimal a gate valve is better?

Palmer