Help Silencing My Setup

[JaminRat]

Hi all,

I'm currently setting up a new system and is the first time I've used a sump system. I'm having a few issues getting the noise levels down.

I have an internal overflow fitted with a durso standpipe.

(not a great pic but you can see the setup)
From here the pipework drops vertically 7" through a ballvalve into 45 bend drops a further 10" (vertical drop approx 15" pipe) through a 90 bend and into another length of rigid pipe and ends approx 2" below the water level in the sump.

Water is then returned by an eheim 1250.

I have done the following to try and resolve the gurgling sound.
1. Fine tuned the hole size to get the water level in the weir at approx midway on the durso and stable. (worked but gurgled)
2. Fitted some filter floss into the upright section of the durso above the waterline to deaden the sound resonating through the pipe. (Better but still gurgles)
3. Throttled back the ballvalve on the drain and have almost eliminated the gurgle. I'm not overly happy with doing this as a small blockage could end with disaster

The problem now is the sound of the water entering the sump and I'm not sure where to start resolving this and the remaining gurgle.

Sorry for the long post but often more info is better.

 

[SkiFletch]

Anyway you can take a pic of the other end down in the sump? I've got some ideas that will depend on how you've constructed it

 

[JaminRat]

Yep I'll take some pics this evening but please remember I'm only wet testing so it may not be pretty

 

[JaminRat]

Sorry for the delay I've lost the cable to upload pics but will do so as soon as I find the lead.

 

[SkiFletch]

No need to apologize

 

[JaminRat]

Here we go.
1st up a video the first bit is with the drain restricted (using ballvalve) to get it running as quietly as possible second half is with the ballvalve fully open and the hole on the durso fine tuned. You can hear the difference.
Link

Finally just a few shots of the plumbing. note it's slightly different from the original description as I was trying to improve things.

 

[SkiFletch]

Ah, ok I see what's going on. Your overflow is very over-sized compared to your pump output. Are you restricting the output of the return pump with any valves currently, or is it wide open? If its restricted, start by opening it up a bit more to force the drain to suck more water and less air. Then, to silence the other end where it enters the sump, I can think of 2 methods. First would be to have the drain empty out on a piece of angled plastic that points towards the wall of your sump. Basically instead of having the water enter the sump under the water level, it hits this barrier and is deflected towards the wall. The other method i can think of, is to have the drain enter a very large block of large-cell foam just above the water level. This too should eliminate taht bubbling/sloshing sound, but obviously will need periodic cleaning.

 

[JaminRat]

Thanks Ski. The pump output is full on. The additional plumbing is in case I needed to restrict the output but is currently unused. I like the idea of the angled plastic and I'll give it a try in a few minutes. It's odd as the drain is actually undersized for the pump size but I have read supports of Durso's handling a lot more flow than they are rated for. If memory serves someone claimed 1000gph from a 1" bulkhead so I think you may of hit the nail on the head.

I'll try it now and report back.

 

[JaminRat]

OK so got no foam here at the moment only filter floss or Juwel carbon sponge but tried the plastic idea with little success.
I have tried a couple of ideas and seam to have resolved it.

I have used flexible tubing insted of rigid pipe below the waterline to 'cushion' the water a little more and have done the following to reduce the amount of air entering the drain.

Blocked the hole in the Durso.
Throttled back the drain until the water in the weir was bouncing up and down but only between the same margins.
Slowly opened up the hole in the Durso until the level was stable.

It's now running very quitely there is still air coming through the drain as I can see a few air bubbles so the overflow is not running as a syphon. I'll try shutting it down and restarting it in a minute and if it restarts the same then then this will be the solution otherwise 'I'll be back' LOL