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View Full Version : Overflow silencing project --no room for a Durso.


dg3147
01/11/2010, 11:51 AM
I need some ideas to help silence my overflow box. The space does not appear to allow for a Durso or Gargle Buster. The noise is due to an 18" waterfall affect as water pours into the overflow and to the bottom (i.e. not a toilet flushing noise).

So far I have tried adding bioballs with a filter sponge on top of them, this has reduced the sound about 25%, but it's still quite loud. I also built a small acrylic canopy and a put it on top of the overflow which reduced sound another 5-10%.

The structure of the current design has a 1" return line that is T-shaped that blocks me from adding a durso to the 1" dain line. Below is a diagram.

Should I add a gate valve to my return line and decrease return flow; therefore, decreasing the turbulence of water going through the overflow teeth? (I am concerned however about dropping the DT water level further into view). Any other ideas?

Help! :eek:

der_wille_zur_macht
01/11/2010, 11:58 AM
DON'T use a valve on the drain to control flow - that's asking for trouble, except in the rare case of a drain system purposely designed to incorporate a valve (i.e. bean's system.)

Can you simply abandon the return configuration? Maybe have it just exit on the left side in the diagram you drew?

Also, check out stockman drains. It's a different take on the Durso concept (separate air and water intakes, submerge the water intake) that often fits in far tighter overflow boxes.

dg3147
01/11/2010, 12:06 PM
The tank is up and running, so pulling out the return line and altering it is not really an option. The T-shaped return line runs right over the top of the drain, so there is no room to place an additional structure (such as a HGB of Durso) on top of the drain line.

I did not mean that I wanted to restrict flow from the overflow down to the sump (which would silence it by raising the water level inside the overflow), that of course would be inviting disater. I ment restricting the return flow to the tank; therefore, creating less turbulent water flowing over the teeth into the overflow. Hence, maybe more laminar flow going down the overflow sides to the bottom. But again, I am concerned about decreasing my flow throught the whole system a bit too much and also lowering water level in the DT.

widmer
01/11/2010, 12:08 PM
I did a really simple mini mod of a durso for mine, made it from deafeningly loud to silent. I'll take pics when I get home this evening and put them up here to show you. PM me if i forget and you're still interested if they aren't up by ~7 PM

jbird69
01/11/2010, 07:19 PM
how high is your drain pipe sticking up into the overflow? The water in the overflow will be as high as the drain pipe, If the top of your drain pipe is 1" below the top of the overflow, you will get a much smaller waterfall.

dg3147
01/11/2010, 09:29 PM
there is no drain pipe --that's the problem. And no way to squeeze one in now that the return is plumbed and the tank is up and running. Dang LFS put the overflow together for me and, as a newbie, I didn't realize the problem until it was too late. He said it would quiet with time, but 4 months later clearly this is not the case.

help!

luv4paws2
01/11/2010, 09:40 PM
Is the return glued? If not, just turn the tank off, remove the return, fix the problem, and put it back together.

sedor
01/11/2010, 09:52 PM
I agree, the return shouldn't be glued into the bulkhead!?! Can't you just pull it out, put an elbow on it and add a stand pipe to the drain? Maybe a picture of the overflow box would help us.

widmer
01/11/2010, 09:52 PM
OK I'm pretty sure I'm not the first person to do this. I'm sure it's a modified version of a fill-in-the-blank style overflow, but it's working GREAT for me.

In my case, the standpipe is 1" PVC. Then I've taken a 2" PVC cap and drilled the center out so that it fits over my standpipe, and slotted it as well because it's serving as my main overflow "box". Then I took a 1.25" PVC cap, drilled big circles around the circumference, and cut through them with a saw to reveal all of these half-circles around the base. And it simply sits on top inside of the larger cap. The water level comes up to above the little half-circles when it is in operation. And Finally I drilled a little hole through the top to allow air in. Here's pictures:

http://i276.photobucket.com/albums/kk10/widfis/Image170.jpg

http://i276.photobucket.com/albums/kk10/widfis/Image169.jpg

http://i276.photobucket.com/albums/kk10/widfis/Image168.jpg

Sorry it looks so dirty, you know what they say, the camera adds ten pounds of algae :lmao:

If you already have an overflow box with teeth, you know you could bypass the part where I slotted the larger cap. In fact, I suppose you wouldn't even need something to serve as the larger cap if you can simply & securely suspend something similar to the smaller one over the top of your standpipe, but make sure that thing doesn't have any way to suffocate your standpipe and cause an overflow.

widmer
01/11/2010, 09:54 PM
Just noticed you said you had no standpipe for the drain. Someone correct me if I'm wrong but I think it would be totally fine to make something synonymous to my smaller cap as seen in the picture, and simply set it in the base of your overflow above the drain hole.

jbird69
01/11/2010, 11:13 PM
widmer. That is a sweet little diy you got there! I think the OPs noise is coming from water pouring over the overflow wall, not a noisy drain

kcress
01/12/2010, 12:14 AM
The structure of the current design has a 1" return line that is T-shaped that blocks me from adding a durso to the 1" dain line.

WOW! That is so lame! Your LFS guy should be severely flagellated for this screw up. :uzi:


You have a well stated question, thank you.

There are several ways to work this.
1) The noise from the fall.. Stop the fail. Turn it into a slide. Get a sheet of something that is as wide as your overflow and high enough to reach up to just below the teeth. The water flowing over the teeth will run down the sheet of material quietly reaching the bottom.

If you can't get enough angle on the sheet to have the water run down it, instead of fall off of it and land at the bottom, (same as now) , then you need to use something with lots of corrugations, so the water loses energy all the way down. Something like stiff plastic window screen. Or the plastic screen sheeting used in turf scrubbers.

2) Fix your existing screwed-up returns. Yes you can do this now! Turn off your pump, turn off your return valve, turn off the drain valve, to isolate all your returns.

Now you can unscrew your return piping inside the box. The tank water will flood your overflow box then stop once the box is full.

Now you just work in the box filled with water. Pull that totally lame-*** T out. Put in a new T that has the center port outlet facing the left outlet hole. This one just gets re-plumbed the same as you had it. Now you have the other T outlet pointing straight up. Ignore it for now.

Make a standard Durso or exactly what widmer suggests up at about the correct height.

Now just put together whatever fittings you need to have that remaining return: A) plumbed back to its hole in the overflow. B) Plug the hole on the overflow with a fitting and plumb that second return into a LocLine that comes up out of the overflow and can then be pointed wherever you want it instead of just out sideways. Or multiple LocLines to point several directions.

Note too that the piping that continues up and over can all be slip joints that aren't glued. Just wrap the PVC with a little Teflon tape and you will get tight removable joints. That would allow easy servicing of whatever overflow device you use.

bradleym
01/12/2010, 02:38 AM
kcress,

I'm tagging along for my own setup and I just tried your idea with the turf scrubber material on my new zeroedge overflow tank return. Nice tank but it has two rectangular returns that roar after a ten inch drop. I found that the best setup for me was to cover half or more of the opening with a horizontal sheet and that would cause the rest of the deflected water to hit the opposing wall and slide down quietly. It's not silent but I have a TON of flow so even a 50% decrease was a relief. Thanks!

dg3147,

If you try this approach I thought this might be helpful to you also. You could just lay something over the return T and leave the back side open to let the water run down the back wall. Once it's on the wall it hits the bottom alot quieter, and you can leave your bioballs, filter and canopy in place to dampen that. The only trick would be supporting the front edge so it fits flush to the front and just under the teeth... Good luck!!

kcress
01/12/2010, 05:32 AM
bradleym; Thanks for the feedback! :thumbsup:

A picture would be useful if you've got one. :dance:

bradleym
01/12/2010, 03:50 PM
Let's see if I know to post a pic...

bradleym
01/12/2010, 04:05 PM
:rolleyes: Ok... Try 2.

bradleym
01/12/2010, 04:11 PM
Yay! Ok now that there's a picture - the water rushes in most heavily at the bottom of the image, originally falling through the rectangular area about 10" before hitting bottom. In this picture the water is slowed by the mesh but most of it is turning to the right instead of falling through, where it hits wall just past remaining open area on the right. The wall doesn't reach the water so it still splashes noisily but this is a HUGE improvement in the volume. Next I am going to attempt a canopy for some additional silencing.

kcress
01/13/2010, 12:55 AM
That worked! Thanks.

dg3147
01/14/2010, 12:52 PM
As suggested above, I end up tearing out the old plumbing and extending the stand pipe. This solved the waterfall affect leaving only the gurgle sound. Later today I plan on adding on an HGB.