Durso Gurgle

[Koddie Doo]

So every couple minutes the level in my overflow falls about 1 inch. Then it gos back up and a couple minutes later it falls again. Any clue why?

I thought maybe the vent tube was clogged, but it is not. It would not be such a big deal but the way my sump is run that when that much water comes down it goes over the back side of my sump and the i have water on the ground....

The durst are was came with the marine land tank.I built my last ones and no problem.

Durso by kmw504, on Flickr

Thoughts?

 

[kegogut]

It sounds like you have too much flow going thru it. Adjust your flow a bit and that should work.

 

[sbeason]

Turn down the flow on your return pump from your sump back to your tank; hopefully you have a ball valve already installed.....

 

[Greybeard]

Pull the bit of tubing out of the vent hole on top. You're system is 'surging'... meaning that it's flowing enough to get a siphon started, exceeding the flow of your pump, which lowers level in the overflow box, loosing siphon, lather, rinse, repeat.

More air entering the vent should help.

Oh, and I highly recommend migrating to a Herbie style overflow

 

[mpgrant77]

+1 on reducing the return pump flow. Mine does the exact same thing if I increase the return pump flow. The durso has two siphon speeds. The first is normal drain speed. This is the amount of water than can flow down the pipe without the drain going to full siphon. The second speed is full siphon. This is a much faster flow or surge as greybeard mentioned. Trying to run a durso overflow at full siphon is difficult without a second overflow pipe so most of us with a single durso run at the normal drain speed. The idea is to regulate your return flow so that you do not pump more water than your return pipe can handle at normal drain speed. If your return pump is returning more water than the pipe can drain the overflow will begin to fill more and more until the return pipe is submerged, which at this point the air pushed out of the drain pipe neck and it goes to full siphon. You get a large flow of water that quickly drains down your overflow until the water level drops and allows air into the neck of the drain pipe. Once the air breaks the siphon the return pipe drain speed drops back to normal. Hope that made sense and or helps.