dual durso

[kngfisher]

So al looking for someone who has done this.....I have a dual durso setup in my single overflow (6x10x6) 90 gal display tank feeding down to a 20gal sump and want to increase the drain rate to enable me to take more advantade of ehiem 1262 to feed the display rather than pumping so much water back into the sump.

 

original

single 1.5" durso, 2" bulkhead, 1.5" drain (no bends) - {lots of flow but lots of bubbles}

ehiem 1262 return pump (in-sump) to wavySea+

diverting water that overflow/drain can not handle back to sump via "T"

 

now

single 1.5" durso, 2" bulkhead, 1.5" drain (no bends) - {almost no flow for some reason}

single 1.25" durso, 1.5" bulkhead, 1.25" drain (no bends) - {lots of flow but lots of bubbles}

ehiem 1262 return pump (in-sump) to wavySea+

diverting water that overflow/drain can not handle back to sump via "T"

 

unable to see improvement from single durso setup to new dual durso setup. wonder why. seems all that changed was that intead of water being split between each of the durso standpipes, the smaller of the two takes most of the load....I guess I have a redundent solution now but did nothing to increase performance as I originally intended....

[dhoch]

A couple of questions:

 

1) are they exactly the same in terms of length? (the dursos... otherwise one will be used to it's capacity before the water gets tot the point where the 2nd one is used...)

 

2) are they both in the same overflow box? (if so maybe the overflow box can't handle the flow the teeth only let through so much water

 

3) Did you alow more flow into the tank?

 

Dave

[kngfisher]

A couple of questions:

 

1) are they exactly the same in terms of length? (the dursos... otherwise one will be used to it's capacity before the water gets tot the point where the 2nd one is used...)

2) are they both in the same overflow box? (if so maybe the overflow box can't handle the flow the teeth only let through so much water

3) Did you alow more flow into the tank?

 

Dave

 

1) yes, dursos are the exact same length....only diff is the PVC diameter.....1.25" (with a 1" reducer into the bulkhead then back to 1.25" drain) vs 1.5" all the way into the sump and it is the one with the smaller diameter that is taking most of the water back to the sump for some reason.

2) yes, both are in the same overflow box (is there a calculation that can be done to determin how much water can flow thew the teeth) number of teeth vs distance of teeth spacing vs teeth hight = X?

3) did not direct more water into the display once 2nd durso was put online, just observed water level of display tank....was expecting water level to drop in display as a result of more water being drained into sump. I had cut more teeth in the overflow prior to this change. All teeth are appox. 1/8" wide and 1/8" apart and 1" long (1/2" above water line, 1/2" below the water line).

 

The return is flexible 1" tubing with a "T" and ball valve that diverts excess water back into sump

[dhoch]

Well I'm sure there is some physics behind why the smaller one is taking the flow and they are not sharing it, but regardless you can increase the flow into the tank a little at a time and you should see the overall through put through the other one increase (up to the limit of how much flow through the teeth that can be handeled.

 

I seem to remember reef central had a calculator based on the size of the teeth and the length of th box, but not 100% sure.

 

Dave

[YBeNormal]

http://reefcentral.com/calc/drain.php

 

Input the gallons/hour of your return. Calculate the open space between the teeth in inches and make sure it is equal to or higher than the recommended linear flow.

[dandy7200]

Remove the new durso and replace with a short standpipe 1.25" dia. Put a gate valve on it and turn the 1262 on full blast. Adjust the gate valve to tune your durso is much easier than a dual. Basically you want to choke the 1.25 pipe so that it is only getting about half the flow approx and the rest will go down the big durso.

[flowerseller]

With the additional durso, the water level in the display should not have droped but the water level in the overflow box should have.

Did it?

If you increase return flow, the display level will rise with or without teeth since regardless, only so much water can overflow into the box at a time. The only way to avert that is allow more surface area (bigger box) for water to flow over. Reverse holds true if you decrease flow to the display. level will drop

Have you tried taking the durso part off and simply allowing the water to overflow the stand pipe?

If you are concerned about noise there are several things you can try but both need to be the same height;

putting a 45 on each stand pipe

putting a 90 on each stand pipe

placing a piece of sponge filter completely over the box area but not so so it will allow water to contact it.

Make sure that the overflow line to the sump is not under the water as this increases back pressure creating more noise.

[kngfisher]

http://reefcentral.com/calc/drain.php

 

Input the gallons/hour of your return. Calculate the open space between the teeth in inches and make sure it is equal to or higher than the recommended linear flow.

Eheim 1262 Universal Pump:

* Pump Output: 900 gph

* Delivery Head: 11`6"

Using the following input parameters

Gallons per Hour = 900

Drain and Overflow sizes are calculated as

Recommended minimum drain pipe diameter = 1.24 inches

Recommended minimum linear overflow size = 14 inches

 

These calulations do not make sense because

* display has 22 linear inches of overflow (6x10x6)

* drain pipe diameter was 1.5"

and yet the return pump would still overflow the display hence the experiment with dual drains

 

With the additional durso, the water level in the display should not have droped but the water level in the overflow box should have.

Did it?

maybe a 1/8"

 

If you increase return flow, the display level will rise with or without teeth since regardless, only so much water can overflow into the box at a time. The only way to avert that is allow more surface area (bigger box) for water to flow over. Reverse holds true if you decrease flow to the display. level will drop

Have you tried taking the durso part off and simply allowing the water to overflow the stand pipe?

tried that well modified.....left original durso inplace and left 2nd standpipe open on top....short standpipe few inched under water line...result....durso flowed less water, water level in overflow dropped....water level in display rose...

If you are concerned about noise there are several things you can try but both need to be the same height;

putting a 45 on each stand pipe

putting a 90 on each stand pipe

placing a piece of sponge filter completely over the box area but not so so it will allow water to contact it.

Make sure that the overflow line to the sump is not under the water as this increases back pressure creating more noise.

I guess without a durso, I would be cutting down on the amount of tiny bubbles in my sump and sometimes returning to the display....another plus....

[flowerseller]

tried that well modified.....left original durso inplace and left 2nd standpipe open on top....short standpipe few inched under water line...result....durso flowed less water, water level in overflow dropped....water level in display rose...

 

I

 

Are you saying you did not increase flow from return pump, did the above and the level rose in your display?

 

IMO - That's just not possible unless the level in the overflow is the same as the display therefore not actually an overflow anymore.

[DaveS]

Remove the new durso and replace with a short standpipe 1.25" dia. Put a gate valve on it and turn the 1262 on full blast. Adjust the gate valve to tune your durso is much easier than a dual. Basically you want to choke the 1.25 pipe so that it is only getting about half the flow approx and the rest will go down the big durso.

 

Was Googling all over the Internet and lo'and behold part of the answer was right in my back yard. Dandy or others, can you expound on this approach?

 

I have 2 returns in my overflow box. I was going to convert from straight, noisy standpipe to durso. I've seen/read about tuning problems and have seen this gate valve approach. My questions are:

 

1) how do I determine the height of the elbow on the durso?

2) how do I determine the height of the straight standpipe?

3) how do I determine the how much to close the gate value to tune the durso?

 

Sorry if these are simple questions, I just wanted to get an idea of what I need to do before I start hacking away.

 

Thanks!

[dandy7200]

Was Googling all over the Internet and lo'and behold part of the answer was right in my back yard. Dandy or others, can you expound on this approach?

 

I have 2 returns in my overflow box. I was going to convert from straight, noisy standpipe to durso. I've seen/read about tuning problems and have seen this gate valve approach. My questions are:

 

1) how do I determine the height of the elbow on the durso?

2) how do I determine the height of the straight standpipe?

3) how do I determine the how much to close the gate value to tune the durso?

 

Sorry if these are simple questions, I just wanted to get an idea of what I need to do before I start hacking away.

 

Thanks!

 

1. Center of the Tee should be about 2" below the overflow

 

2. 0" Just put a screen on it.

 

3. Enough that the water level raises up to the durso intake.

 

 

What this does is takes almost all of your flow and pushes it throught the lower standpipe with NO AIR. Your durso acts as a safety overflow and takes just a bit of water to level the water in the overflow box.

 

Try a search for Herbie Overflow.