External Durso Opinons

[HKAVR45]

I am looking into drilling/overflow box configurations for my 40g breeder. Because having a relatively 'shallow' (distance front to back) overflow box is important to me I have looked into placing an External Durso's outside the tank and an elbow pointed downward inside the overflow box as shown in the diagram.

Does anyone have any experience/opinions regarding these in terms of noise and flow?

Thanks.

 

[smcnally]

I've done something similar and it was pretty quiet.

 

[HKAVR45]

Thanks for the feedback. How about flow? Do you think I could get 600GPH max out of a 1" bulkhead using this setup? Ideally I would have about 400GPH going through the sump, but I want to make sure the overflow can more then handle the return.

 

[mloebl]

I did something very similiar except I notched the 1.5" pipe in the tank as I couldn't add an overflow since the tank was up and running. I get excellant flow, and I very very little noise. I have the tank behind my couch in the living room about 3' from my head, and can barely hear a trickle even if the room is dead silent.

-Mike

 

[HKAVR45]

When you say you notched the 1.5" pipe, do you mean you have a 1.5" bulkhead minus the skimmer box?

I don't know if I'll be ok with either of the following setups:

1.) 2 X 1" bulkheads in the same over flow box 6 inches apart.
2.) 1 X 1.5" bulkhead dead center

The main goals are a.) at least 400GPH flow, b.) redundancy in terms of preventing a clogged drain resulting in a flood.

 

[mloebl]

When you say you notched the 1.5" pipe, do you mean you have a 1.5" bulkhead minus the skimmer box?

I don't know if I'll be ok with either of the following setups:

1.) 2 X 1" bulkheads in the same over flow box 6 inches apart.
2.) 1 X 1.5" bulkhead dead center

The main goals are a.) at least 400GPH flow, b.) redundancy in terms of preventing a clogged drain resulting in a flood.

Yeah, unfortunatley I couldn't do a skimmer box inside as the tank was up and running (I drilled a running tank.) What I ended up having to do was take a 1.5" pipe out to a T from the 1.5" bulkhead and cut notches on one end to allow surface skimming. The other end I drilled some very small holes and capped it. On the outside of the tank I have another T with the top capped with a hole drilled into it for air to escape. Not the best solution in the world, but even with my limited options I still get good flow and it's quiet.

-Mike

 

[HKAVR45]

Mike,

Nice idea, I saw that on Nano-Reef.com.

So what do you think? 2 one incher's or one 1.5 incher?

 

[mloebl]

I would think a 1.5" drain would be less likely to clog and less plumbing. However my logic could be flawed, however here's my thoughts on 1 vs 2 holes (please correct me if wrong); when you adjust the flow of your return pump so the water coming down the drain from the overflow matches that of the return pump, no matter how many holes any clog could cause a flood. Since it's balanced, I would think even if you had 10 holes, if any of them get clogged so the draining is reduced, you will risk a flood.

If you are highly concerned about flooding, what about using a float switch similiar to how the top off works except reversed. IOW, if the float switch is off, the return pump flows, however if there is a raise in water level due to no flow down the drain, the float switch would turn on and shut off the pump. Just my .02 but I'm not as experienced as some of the other people on here so there may be other factors I'm not considering.

-Mike

 

[Biotoper]

I have the setup in the pic, except just a screw-in filter nipple rather than an elbow pointing down. I don't know if the elbow does anything for sound reduction. I have tubing inserted down the durso cap hole a few inches which deadens any gurgling, so all I hear is a very soft trickling from water falling over the skimmer lip to the level in the overflow box. Reef Central has a calculator for how much flow an X" inch bulkhead can handle. I think 1 x 1.5" would be fine.

 

[Biotoper]

I would think a 1.5" drain would be less likely to clog and less plumbing. However my logic could be flawed, however here's my thoughts on 1 vs 2 holes (please correct me if wrong); when you adjust the flow of your return pump so the water coming down the drain from the overflow matches that of the return pump, no matter how many holes any clog could cause a flood. Since it's balanced, I would think even if you had 10 holes, if any of them get clogged so the draining is reduced, you will risk a flood.

That is not quite correct. You don't "adjust" your return pump to "match" the water coming down the drain. As long as your overflow(s) can handle the flow from your pump, then the water coming down is automatically the same as that going up, even if the overflow(s) can handle much greater flow. You are correct in that if you want to have a 2nd truly redundant bulkhead, then you want to use a pump no greater than what a single bulkhead can handle.

So 2 x 1.5" is needed rather than 2 x 1", if one wants >1" worth of flow and redundancy.

Ryan

 

[mloebl]

That is not quite correct. You don't "adjust" your return pump to "match" the water coming down the drain. As long as your overflow(s) can handle the flow from your pump, then the water coming down is automatically the same as that going up, even if the overflow(s) can handle much greater flow. You are correct in that if you want to have a 2nd truly redundant bulkhead, then you want to use a pump no greater than what a single bulkhead can handle.

So 2 x 1.5" is needed rather than 2 x 1", if one wants >1" worth of flow and redundancy.

Ryan

Good point, thanks for the correction.

-Mike

 

[HKAVR45]

I apologize as I didn't supply enough info which caused confusion.

The 1.5" would be a single drain down to the sump.

The twin 1" drains would be separately plumpbed into the sump giving me some form of redundancy if one were to be partially clogged.

And on top of that I plan to use a Quiet One 3000 which pushes about 400GPH at a 4 foot head.

 

[JohnK]

I would assume that 1 x 1" drain would easily handle 400gph, so 2 x 1" drains would cover "flow and redundancy"? No?

 

[Bobbofin]

I have the exact same set up as HKAVR45 has in the first post picture except I have a 1/8" hole drilled in the the cap on the tee instead of a valve. It works great! I did the notched elbow/strainer on the bulkhead like mloebl stated when first starting the tank. It sucked air, was noisey and water and air sprayed out like a fuel injector down in the sump. I only have a 30 gallon tank so I drained all I could into the sump and buckets. I then ordered a overflow from www.wetdryfilter.com to put up in the corner. Christian is awesome. He and I sent emails back and forth and he made me a black 6" x 6" x 4" overflow that I glued into the corner with black silicone. I put a street 1" 90 upsidedown like in the pic and it is SILENT! 1" drain will do 600gph.