After trying to fit durso stand pipes into my overflow unsuccessfully I came up with this simple solution. Its two 6" sticks of 1" pvc pipe with 1/4" holes drilled into it below the water line. Caps with 1/16" holes drilled above the water line to allow air in. I started out with 3 holes below the water line and added 1 at a time untill the water was at the level I wanted, 6 holes in each pipe total for my setup. It is now totally silent.