Durso Problem

[stoppiesteve]

So I just setup a tank that has an overflow and sump, but was just a simple pipe connected to the bulkhead at the bottom of the overflow. It was LOUD. I built a Durso and it's nice and quiet now. However, I am worried that I may have made the intake too high, or the air holes on top too small. For one, my water in the overflow is only about 1.5cm lower than the tank water. Secondly, the water in the overflow will slowly rise, and then every few minutes it will "burp" a bit and then the water level in the overflow drops about 1cm. Then the cycle repeats where the overflow water level gets higher, another burp and it drops again. Do I just need larger air holes in the top of the durso, or do I need to cut the PVC so the elbow is lower in the overflow?

Also, is there any problem with having the water level so high in the overflow? Should it be several inches lower than the tank's water level?

[Ross]

Just drill out the holes bigger, problem solved.

The only problem i see with the water level being so high in the overflow, is that it could drain more and overflow your sump. This would only be the case if your standpipe was alot lower than the water level though...

[LoneStar]

I have seen people add small ball valves (like the ones used for RO/DI) to controll the air in the durso pipe set-ups...

[brewercm]

I had to do what LoneStar said because my hole was too large and the water level got too low and I ended up with the constant sucking sound again. Easy to adjust it out that way.

[Marlin]

Sounds like you need a larger air hole to eliminate the burping. I did what Lonestar said, I can control the amount of air coming into the top of the Durso and fine tune it so I do not get the burping and I maximize the amount of water that flows to the sump.

[jc]

I used to have a problem with the burping sound and lots of microbubbles. I put on a filter sock to get rid of the bubbles about 3 months ago. Since then I have taken the sock off and the bubbles are gone. Also the burping noise slowly went away. I think the tank just had to have a break-in period. Has anyone else noticed problems like that just go away on their own with time.

[Bill S]

It may be a different problem. Sometimes, if you have the water coming in from the side, there may not be a good avenue for enough air to go thru the durso. On one of my drains, I had so much water coming thru that it couldn't suck any air in from the Durso. My solution was a couple of pieces of 1/2" OD tubing thru the top of my durso, that go down and UNDER the flow of water coming from the "T". Sory about the lousy artwork!

[stoppiesteve]

Wow, thanks for the great replies. Whenever the system burps, there is a slight spurt of air bubbles shortly thereafter. I sort of like the effect as it appears more natural, but I will try drilling more holes in the cap of the durso. If that doesn't work, I'll try the airline.

Thanks for all the help here. I just moved back to SA from College Station, and am extremely glad to see all of this support for the hobby, especially locally. Thanks again.