Noisy downpipe

[Guest Jonny M]

Hi All,

 

Just been reading your suggestions regarding noise reduction for an overflow.

 

I've just set mine up for the first time as I'm moving from a 4ft tank with hang on overflow box to a 5ft with holes drilled in the back and a right angle bend inside the tank to the desired surface level.

 

I have one drain/overflow at either end. They both go out the back of the tank and into a right angled drain. One goes from the back top right of the tank to the to the back bottom left of the stand at a 45' angle, and into the sump. This one is quiet enough.

 

The other goes from the back top left straight down to the back bottom left of the tank and into the sump but is very noisy.

 

It's not the sucking air slurping noise you commonly get with overflows but is water rushing down the pipe since it's vertical. Any ideas how to stop this noise.

 

The pipes are 50mm diameter (I decided the bigger the better......hmmmm, was I wrong?)

 

I've tried submerging the return pipe that is noisy but this makes little difference. IT is sucking air through it tho although this isn't creating a sucking/slurping noise at the top end.

 

I was thinking I could reduce the exit diameter of the pipe to allow the water to back up the pipe and fill it eliminating the noisy cavity but I'm a little reluctant to reduce the flow.

 

Any ideas?

 

Cheers

 

Jonny M (UK)

[BeltwayBandit]

That is a simple one. Just put some elbows in the pipe. 2 90 degree elbows about a foot above your sump will break up the flow and slow it down so you don't get that rushing water sound.

 

BB

[Guest Jonny M]

cheers. I'll give that a go. The drop is about 2.5 ft with a right angle at the bottom into the stand then a right angle down into the sump. I'll try and put another two in the drop to see if it helps.

 

thanks again.

[Norboo]

few elbows did the trick for me.