wet/dry overflow makes TOO MUCH noise

[Pieface]

I'm not a big fan of restricting the the output of the return pump. It work's but I'd rather let the pump do it's thing and size the intake to handle any variation in the return pump output.

The Durso let's you tune the water level in your overflow box as cchhcc said. A smaller air hole in your durso will raise the water level a larger hole will lower it so ity's better to start small with your air holes or build them with adjustability.

Here's a picture of where I have the level sitting in my overflow. With the water only dropping 15mm or so into the box this part is near silent.

Ignore the green wall-plug in these pictures, the air flow should all be controlled through the end cap of your tee piece and is configured this way on my current set-up:

I have since added a 20mm siphon over the side into the tank into the overflow box. With the use of a control ball valve the siphon takes about 95% of the flow and the durso takes about 5%. At this low flow rate the water runs down the side of the durso rather than falling (as you can see in the photos) this makes the intake side of the sump run near silently.

HTH

 

[JoelR]

If you have a hang on back overflow box you can put a wad of filter pad in the open end of the return pipe (the part that sticks out of the water). You can also cut a piece of plexi to cover the whole back chamber. Just make a notch for the siphon tubes. You'll have to flip the cover every few weeks but that's no problem.
Do both those & it makes a huge difference.

 

[FSM]

I need to make one of those standpipes...I tried before, but I drilled too many holes I think. The water level just kept rising, and since I made it very tall, I was worried it was going to overflow the corner overflow (haha) before it created a siphon. I'll probably try again but make it lower down.