Durso question

[saltyhog]

A friend has a 90 gallon with a corner overflow that came with Durso and a return line plumbing. The Durso is 1 1/2" that narrows to a 1" bulk head and has a tube with an opening at the top of the upward ell. There are also two large holes in the downward ell just above the opening. He has a return pump that's moving a little over 700 gph (without accounting for head pressure).

The water level in the overflow rises to above the horizontal middle of the Durso and then rapidly drops below the opening and then starts that all over again.

How can I help him fix this? I've always run a Bean Animal and know nothing about a Durso.

 

[AllSignsPointToFish]

Sounds like an intermittent siphon. Can he slow the pump down or throttle a valve in the pump discharge?

 

[Rjramos]

Did you mention upward ell? I went to see a friends tank for similar problem and it turned out the ell on the durso was upward. The opening to the durso where the water goes in should be pointing down. Show a picture of it to confirm.

 

[saltyhog]

Did you mention upward ell? I went to see a friends tank for similar problem and it turned out the ell on the durso was upward. The opening to the durso where the water goes in should be pointing down. Show a picture of it to confirm.

There are two 90 degree ells that make up the fitting at the top of the drain. There is a tube in the top as it turns horizontal and then the other ell completes the 180 degrees and points down. Sorry for the confusion. It looks just like the open stand pipe on a Bean except for the extra holes just above the opening of the drain.

 

[Rjramos]

I need a picture or video. The top end of dursos I've seen and installed have from bottom to top. A tee with a 90 ell pointing down, just water goes in through the bottom. Water should be midway or slightly above the center of the tee. Above the tee is the cap, this should have a small hole where air is introduced into the standpipe. The amount of air allowed to go through by the size of the hole is what adjust the level of water along the standpipe. Start with a very small hole and increase the size according to the water flowing until the water is steady at the center of the tee and the noise stops .

 

[AllSignsPointToFish]

Theoretically, you don't have to have a tee and an elbow. You could accomplish the same setup with two elbows and a small hole drilled into the elbow that is directly connected to the standpipe:

However, most durso overflows looks like this:

Which one does your friend's setup look like?

 

[AllSignsPointToFish]

The cycling water level you speak of is due to siphoning. Make the hole in the elbow bigger or slow the pump down if you can.

 

[MaiReef]

put a valve in the pump line and slow it down. That will be the easiest.

 

[cromag27 Verified Sponsor]

The durso does best at 1 1/4" diameter or more. downsizing it to 1" at the bulkhead is creating issues.

 

[Rjramos]

The durso does best at 1 1/4" diameter or more. downsizing it to 1" at the bulkhead is creating issues.

Negative on the reduction to 1" at the bulkhead. I agree on the 1 1/4" +diameter on the durso piping, but a 1" bulkhead is sufficient in this application.

 

[cromag27 Verified Sponsor]

No. I have plumbed more of these than I cared to. by using a smaller diameter bulkhead, you throttle the flow. you'll either end up with the flushing syndrom or you'll need to reduce the return flow way down. neither are ideal.

 

[justingraham]

Aren't all reef ready tanks one inch bulk heads? I don't think there's anything u can do about that

 

[cromag27 Verified Sponsor]

Drill a bigger hole if there's enough room.

 

[justingraham]

Aren't most reef ready tanks tampered bottom glass? I'm asking cause I'm in the same boat

 

[cromag27 Verified Sponsor]

Reef ready can also be a custom built tank by someone in their garage. it doesn't necessarily mean it was built by a large manufacturer.

Either way, some tanks have a tempered bottom and some don't. check with the manufacturer.

 

[Rjramos]

Reef ready can also be a custom built tank by someone in their garage. it doesn't necessarily mean it was built by a large manufacturer.

Either way, some tanks have a tempered bottom and some don't. check with the manufacturer.

Anything with a molded overflow or in larger tanks 2 overflows with a plastic frame on the bottom and top is a manufactured "reef ready" tank, by companies like Oceanic and All-glass Aquariums. These have a 1" bulkhead and a 3/4" bulkhead hole drilled on the bottom of the overflow. And yes the glass is tempered after these holes are drilled, so trying to make a hole bigger will shatter the bottom. These systems work well with dursos and support great tank turnover rates!