durso question

[balistidae]

i am running a durso standpipe. I am just wondering how much noise it should be making and where the noise should be coming from. I am using 1 1/4 inch pipe. I just read that they can be "silent" and mine definately is not. I know there will be some noise at the sump where the water is very turbulent but i would like to eliminate all other noise..thanks for any input. Greg

 

[robchuck]

Is it making a slurping or sucking noise?
Is enough air flowing through the vent hole on top of the standpipe? The sizing of this hole and keeping it clean are important factors in the noise level of a Durso.