Reverse Durso Application and Construction

Do you have bubbling and/ or splashing noises from the water entering your sump, have you tried almost everything. Here is something that you may have never heard of. It's called a Reverse Durso. It was introduced to me from a Mr. Todd_Sails (username). Since my introduction to this DIY silencer my sump has been free of bubbling or splashing noises.

The Reverse Durso is exactly what the name implies. It is a Durso standpipe that is used upside down and installed directly above the sump to quiet the bubbling and splashing noise caused by water entering the sump. The concept is to allow the air to escape prior to the water entering the sump allowing for a smooth and quiet exit.
I did my research and looked at pictures and this is how I built mine. It is very simple to construct. It is preferable to oversize the piping for example. If you have 1" plumbing then the piping for the Reverse Durso should be 1 1/4"+.

My plumbing is 1" and my first Reverse Durso was also made with 1" because it is what I had lying around. Even with the Reverse Durso the same size plumbing from the overflow it was still fairly quiet. Since I built my 2 new Durso out of 1 1/4" piping it is much more quiet and virtually silent.

Everything I needed to construct 2- 1 1/4" Reverse Dursos cost me under $10.00 at Home Depot.

What you need: (1 Reverse Durso)
1- PVC T
1- PVC 90 elbow (street elbow if desired)
12"+ of PVC pipe
1- PVC cap
10"+/- airline tubing

Step 1- drill a hole in the PVC cap to allow the airline tubing to slide in, snugly.
Step 2-Cut 2 pieces of PVC pipe long enough to join 2 PVC fitting together.
(If using street elbows please skip step 2)
Step 3-glue PVC elbow to pipe that was cut in step 2, and that to PVC T as shown in picture. (If using street elbow glue elbow into T)

Step 4- slip cap with airline tubing onto the 12" piece of PVC pipe. (This piece I did not glue because if I need to add a longer piece of pipe to allow more air I can always swap it out.)
Step 5- slip PVC pipe with cap into the top of the T as shown in picture in step 3.
Step 6- glue reducer fitting (if using oversize diameter piping other than original plumbing size) into the top of the PVC elbow.
Step 7- (the body of the Reverse Durso is complete) slip the Reverse Durso onto plumbing above the sump
Step 8- (depending on the height to the waterline in sump) cut to fit PVC pipe to be inserted to the bottom of the T so the pipe will go just below the waterline of the sump.

This should complete your build and installation of your Reverse Durso overflow drain silencer. You can now enjoy your setup without the loud splashing or bubbling of water into your sump from your overflow.

 

Edit: after knowing the correct height of the vent pipe. I went ahead and glued it in place.

 

Pro. Nice write up Will.

 

That's a pretty slick idea. I'm gonna have to do this one. Thanks

 

nice idea..you explained it very well and the pics deff help..might give this a go..

 

Thanks jkat!

The reason I did this is because when it was suggested to me I had a hard time finding info on exactly how it was done. I was able to find pics but that was really it. I searched 3reef and couldn't find anything on how to build so I wanted to share with my fellow reefers what I did that worked for me. I give all my thanks to Todd for the suggestion.
If anyone has any tips that they would like me to add or anything that I'm missing please pm me or post a message. All feedback is welcome and greatly appreciated.
Thanks all for the comments and support.

 

It's always good to share your builds and do write ups. I've seen this around, just never heard it called a reverse Durso. Which is fine. If it stick then at least folks will know what to call it.

But I like your "full" version with longer vent pipe and cap to prevent mist/bubbles/salt creep.

I had a ton of bubbles in my sump. This was suggested, but I tried other stuff. One thing I noticed was you have two drains right? If the piping isn't big enough, you can still sweep bubbles along into the sump. Your suggestion to use larger piping is correct. And what I mean is that for the water you flow, with only one drain, you may still get bubbles through the drian

What sweeps bubbles along is velocity. So the fast the water flows, the more bubbles sweep along. A longer drain pipe will also help.The deeper the pipe in the water, the deeper the bubbles have to go and the less you have. So you decrease velocity by enlarging the piping, or turning down the flow. Having two drains is the same as larger piping. Which is just one of MANY reason you only flow enough water to your sump that you need. Extra is not better.

Nice job.

 

Thanks Powerman.

It is the name I was suggested to look up and through google searches is what came up in pictures etc. I did not pick the name. If I did it would be called the "Diverdan Drain Silencer" lol.

When I originally built it I did it out of 1" (same as my plumbing) and although I quieted down and the bubbling sound subsided it still had some bubbling sounds. The oversize piping was the key to silencing like you said it decreases the velocity the water enters the sump. It basically allows less water to flow through a bigger opening rather a lot of water through a smaller opening.

Yes my overflow drain has 2 lines.

Like you specified, this drain also works better if the piping goes further down into the sump, therefore allowing the water to travel further and giving the bubbles a longer amount of time to travel upwards and put the vent.

When I had only the one inch lines with the airline tubing I would on occasion hear the water bubble out the end of the airline and that was actually a good indicator that I needed to open up and expand the size of my silencer.

Thank you for the input and your explanation of water velocity and flow.

 

Diameter decreases, velocity increases, pressure decreases.

 

I have my own variation. Some holes in the middle cap.