My Drain is Too Loud

[Myanth]

Aqua silencer is a great thing. I have built something similar with a standing piece of pipe with abou six hundred hand drilled holes and a piece of 3/8 tube above it to allow air in. You can hear the air rushing in but it is exponentially better. The only worry I have and have almost encountered is the blockage of the drain holes causing an unnerving rise in water level. Thanks again.