Originally Posted by Razarach
So if I reduce my 11 mm feed tube from res to pump I will get lower noise?
I can change pump, but what if I get that sound even after I change pump.
Nope, reducing the feed from the RES to the pump will not reduce the noise.
What I stated prior deals with the taller RES tanks that mount directly to the top of the pump. When the impeller starts to spin, it creates a vortex swirl much like a kitchen blender. This also will sound like a kitchen blender.
Now, to reduce or remove that kitchen blender, a tube or one cut length wise and placed into the RES to just sit there will distort the vortex swirling and therefore no more kitchen blender noise.
Even though Martin shows the DDC-35X, the DDC-1 series and DDC-3 series can do the same similar things to remove the kitchen blender noise.
From Martin's site ...
"With the sponge not working as well as I hoped, I set out to look at the alternatives. I found that the reservoir works perfectly using a top down inlet plus down tube configuration.
This is extremely easy to build, all you need is an extra barb and about 3″ of tubing. Even better would be some sort of clear rigid tube, you just need something to protrude down through the surface of the water in the reservoir and point at the pump inlet. I tested with a piece of 1/2″ x 3/4″ tubing as I assumed that would be readily available by most users."
The Sponge ...
Down Tube ....