Durso adjustment

[rayn]

Im helping a friend dial in his new tank and plumbing. It's a 90 gallon cube with a si glue durso drain. He is running a dc return pump as well.

We can get the overflow to be quiet, but can't seem to reduce or eliminate the noise and large amount of bubbles going into the sump. We've adjusted the durso height, return pump, air intake into the durso, but are still at a loss.

What is the best way to adjust, and how quiet can we expect this to be?

 

[rayn]

Forgot to mention he is using 1" drain and 1" return lines.

 

[AllSignsPointToFish]

Well, since the drain lines will not be completely full of water, you will always have air transport to the sump unless the system is set up for a full siphon (which I don't recommend). However, you can direct the return into a filter sock which will reduce the bubbles significantly.

 

[Maritimer]

An answer I wish I had!

My own system is a double-Durso, and with the valves in the drain lines set wide-open, pulls a lot of air into my sump's first chamber. The first baffle is tall enough that when those bubbles pop, the surrounding area gets pretty wet - and salty. I've found that by partially closing the valves, I can significantly reduce the air entering the sump, but worry that any additional reduction in the drains' flow will overflow the tank. (This was during my leak test - the system currently sits empty, awaiting lights, RO/DI, and my butt to get some work done . . . )

I also wondered about dialing down the outflow from the pump, which also ought to decrease bubbles entering the sump, but haven't tried it yet.

~Bruce

 

[AllSignsPointToFish]

An answer I wish I had!

My own system is a double-Durso, and with the valves in the drain lines set wide-open, pulls a lot of air into my sump's first chamber. The first baffle is tall enough that when those bubbles pop, the surrounding area gets pretty wet - and salty. I've found that by partially closing the valves, I can significantly reduce the air entering the sump, but worry that any additional reduction in the drains' flow will overflow the tank. (This was during my leak test - the system currently sits empty, awaiting lights, RO/DI, and my butt to get some work done . . . )

I also wondered about dialing down the outflow from the pump, which also ought to decrease bubbles entering the sump, but haven't tried it yet.

~Bruce

Running the pump slower does reduce the amount of air transport but does not eliminate it (unless you reduce the flow so low that it is not useful). If you think about the way most piping systems are laid out, you won't be able to eliminate air pockets due to elbows and horizontal runs unless the system is either a completely vertical pipe or is operating under a siphon. Whenever the water trickling down the piping encounters a change in direction, at a 90° elbow for instance, the momentum is reduced as the fluid changes direction. The turbulence incorporates air that is transported down the horizontal runs to the sump. I don't know anyone that has only vertical pipe running between the sump and display tank, and in circumstances where the flow rate is large enough, air pockets will still be entrained and transported in the direction of flow because fully self-venting flow cannot be established. Hope this helps.

 

[SmokinDaReefer]

Would a P trap at the bottom in the sump help with the bubbles? I've been thinking about adding this on mine as well since the bubbles and spray get everywhere and had to make a custom top for that side of the sump. The top makes it annoying to get in there and do any work.

 

[mikeamadio]

My durso is 1.5 inches it's reduced to 1inch (bulkhead size) works great.

 

[AllSignsPointToFish]

Would a P trap at the bottom in the sump help with the bubbles? I've been thinking about adding this on mine as well since the bubbles and spray get everywhere and had to make a custom top for that side of the sump. The top makes it annoying to get in there and do any work.

I would expect that the bubbles will just flow through the Pee trap with the water. Unless you have a large disengagement space that is vented, the bubbles will remain. In fact, the Pee trap may make things worse.

 

[AllSignsPointToFish]

My durso is 1.5 inches it's reduced to 1inch (bulkhead size) works great.

The pipe is bottlenecked at the reduction, so the larger diameter piping may allow disengagement of the bubbles before the reduction. If balanced, the smaller piping could also be operating under a siphon, and both conditions would reduce or eliminate bubbles. That's pretty awesome that that works for you!

 

[rayn]

This tank actually drains straight down. The durso, valve, and drain pipe is maybe 1.5' feet total. We tried a 90 on the end. Then a 90 and a small tube, but bubbles and noise stayed.

At one point we tried a valve on the air intake and got it quiet, but then it wouldn't restart and stay at the right operatic tank water level.

 

[AllSignsPointToFish]

This tank actually drains straight down. The durso, valve, and drain pipe is maybe 1.5' feet total. We tried a 90 on the end. Then a 90 and a small tube, but bubbles and noise stayed.

At one point we tried a valve on the air intake and got it quiet, but then it wouldn't restart and stay at the right operatic tank water level.

The noise can be quieted by extending the drain below the water line (I assume you've already done that). You can also reduce the pump speed which will help somewhat.

I would guess going to a Herbie-style setup is not an option?

 

[rayn]

The noise can be quieted by extending the drain below the water line (I assume you've already done that). You can also reduce the pump speed which will help somewhat.

I would guess going to a Herbie-style setup is not an option?

The drain is already about two inches or so below the water line. Tried farther, tried less.

Herbie or bean would be awesome, but it's a corner overflow in a reef ready tank.

 

[AllSignsPointToFish]

The drain is already about two inches or so below the water line. Tried farther, tried less.

Herbie or bean would be awesome, but it's a corner overflow in a reef ready tank.

How fast are you running your DC pump? Is this still on your 500 gallon system?

 

[morpheas]

Just a wild thought. Use the return line as a drain as well to implement a herbie and return the water with an over the back pipe/tube?

 

[AllSignsPointToFish]

Just a wild thought. Use the return line as a drain as well to implement a herbie and return the water with an over the back pipe/tube?

That's not a wild thought at all...in fact, it's a very good suggestion if the OP can implement it!

 

[rayn]

How fast are you running your DC pump? Is this still on your 500 gallon system?

This isn't my tank. Trying to help a friend. Was there till almost 11 last night trying to figure it out.

 

[rayn]

Just a wild thought. Use the return line as a drain as well to implement a herbie and return the water with an over the back pipe/tube?

I like that! I will suggest that for sure.

 

[AllSignsPointToFish]

This isn't my tank. Trying to help a friend. Was there till almost 11 last night trying to figure it out.

Oh, yeah, my bad. You said that already, but it slipped my mind! How low did you dial back the DC pump? How large is the system? Does it have a single corner drain or dual?

 

[rayn]

It is a jebao pump. We had it turned all the way down at one point. Up to half at one point.

90 gallon cube, not sure the sump. Single corner overflow

 

[AllSignsPointToFish]

It is a jebao pump. We had it turned all the way down at one point. Up to half at one point.

90 gallon cube, not sure the sump. Single corner overflow

Do you happen to know the pump model? Maybe his pump is oversized?