Silent and Failsafe Overflow System

[jcarrel]

BeanAnimal,
That picture was from another poster that I was discussing some ideas with in a different thread (I think, or it may have been this one – it’s so huge it’s hard to remember and it may be in one of these pages somewhere). I had come up with some of my own ideas and posted some pictures in different threads where I was asking some questions about other things. I have built a prototype, done some testing and have been able to establish proof of concept but there are a few things that need a little tweaking still. My schedule has been pretty full so I haven’t been able to get into the shop to build the next prototype but here is where I am with the designs.
Here is the design from my last prototype (some pieces are redundant, multiple views)

And this is my latest revision that I still need to build a prototype for

As you suspected, the siphon does draw a vortex but part of that was the amount of flow I was pushing through the box for testing. At a reduced turnover rate everything was working as I’d expected for my design. I’m hoping adding a little more depth, top to bottom, as well as lengthening the box to better scale for the flow rate will provide enough reserve volume in the box to prevent a vortex. My latest revision should also address a personal criticism I had with my initial designs where some of the redundancy of the emergency channel is compromised. The latest design provides discrete access to the emergency channel in the event of a blockage in the plumbing or baffles for the first two channels and allows for easier up scaling of the design to higher flow systems by simply lengthening the first chamber when building.

It is very low profile (only about 1” proud of the back tank wall), provides the benefit of reduced shadow lines and tank presence without requiring the additional time/materials for construction of an external box to house the elbows. I’d appreciate any feedback you could offer.

I like how low profile it is, but won't this method make quite a bit of noise as opposed to the original 'bean' method due to the ramp of water coming down?

 

[jdcook72]

I like how low profile it is, but won't this method make quite a bit of noise as opposed to the original 'bean' method due to the ramp of water coming down?

Initially, I thought that would be an issue as well. In my first drawings, the top baffle was horizontal but i had the the same thought about noise and revised it to reduce the drop to the leve of the first chamber. But the way it works out with the box being so thin and the large volume of turnover moving through it, the water basically flows as a sheet from the edge of the box to the siphon. There's no space for the water to trickle through. My first prototype has a unfixed top baffle and I can change its position and angle, even when horizontal it didn't result in any trickle noise. Except for when I was pushing the prototype beyond its capacity and I was getting an intermittent vortex, the overflow box is silent as far as I can tell.

 

[DaveMorris]

Would the BA overflow concept work in a traditional overflow as a replacement for Durso standpipes? My overflows in my 300g tank are drilled for two 1.5" bulkheads and two 1" bulkheads. The overflow box itself is 6" x 18" so there would be enough room for the elbows within the overflow. I would be able to use the required three standpipes and still have a hole left over for my return line. Would it work this way?

 

[autodave]

Would the BA overflow concept work in a traditional overflow as a replacement for Durso standpipes? My overflows in my 300g tank are drilled for two 1.5" bulkheads and two 1" bulkheads. The overflow box itself is 6" x 18" so there would be enough room for the elbows within the overflow. I would be able to use the required three standpipes and still have a hole left over for my return line. Would it work this way?

Yes,just make sure they will all fit.

 

[d2mini]

If your siphon clogs,then your open channel (durso with the airline) takes the slack,then your emergency(upturned elbow) is your final drain.
Try to terminate your siphon line about an inch or so in the sump (mine is about 1/2 inch).If you can,do not use the elbow.

I was just reading Bean's original write-up and it says that if the siphon can't handle the flow, the emergency drain (upturned elbow) will take up the slack. And if that drain can't handle the flow, then the open channel turns into a full siphon. And during start-up, water will probably flow down the e-drain. So it seems to me that the open channel air line should be positioned above the opening of the upturned elbow. Correct?

I'm currently trying to push through as much water as possible because I'm running a pretty large pump. My siphon is fully open. The water level in the overflow is right to the top of the bulkheads, completely covering both downturned elbows. The upturned elbow is sticking out of the water about half an inch. Does this sound right?

 

[ataller]

Basemet Sump

Basemet Sump

Before I glue anything...

With my sump in the basement I believe it is best to have to gate valve on the main siphon down in the basement in the sump?

If this is the case, then is dialing in the siphon with the gate valve a 2 man operation ? One in the basement and one by the tank ?


Also, my plumbing is 1.5 inches should I reduce that to 1 inch after the gate valve to further reduce the chance of cavitation ? There is no way I need the full 1.5 inches while running a siphon.

Thanks.

 

[autodave]

I was just reading Bean's original write-up and it says that if the siphon can't handle the flow, the emergency drain (upturned elbow) will take up the slack. And if that drain can't handle the flow, then the open channel turns into a full siphon. And during start-up, water will probably flow down the e-drain. So it seems to me that the open channel air line should be positioned above the opening of the upturned elbow. Correct?

I'm currently trying to push through as much water as possible because I'm running a pretty large pump. My siphon is fully open. The water level in the overflow is right to the top of the bulkheads, completely covering both downturned elbows. The upturned elbow is sticking out of the water about half an inch. Does this sound right?

I would agree with your postion on your airline.
With your siphon fully open,is it running O.K.? Do you have your open channel taking some flow?

 

[d2mini]

Yup, the open channel is taking a lot of flow. Pretty much as much as it can without the water rising in the overflow.
I'll probably be downsizing pumps, but was trying to see how much I could open it up.
Is there anything wrong with the siphon channel being fully open?

 

[ataller]

Before I glue anything...

With my sump in the basement I believe it is best to have to gate valve on the main siphon down in the basement in the sump?

If this is the case, then is dialing in the siphon with the gate valve a 2 man operation ? One in the basement and one by the tank ?


Also, my plumbing is 1.5 inches should I reduce that to 1 inch after the gate valve to further reduce the chance of cavitation ? There is no way I need the full 1.5 inches while running a siphon.

Thanks.

Hate to respond to myself before an answer to my first question but I had an idea. If I am keeping flow under 1000 gph could I use some reducers and then a 1" gate valve at the end of my 1.5" drain?

 

[uncleof6]

I was just reading Bean's original write-up and it says that if the siphon can't handle the flow, the emergency drain (upturned elbow) will take up the slack. And if that drain can't handle the flow, then the open channel turns into a full siphon. And during start-up, water will probably flow down the e-drain. So it seems to me that the open channel air line should be positioned above the opening of the upturned elbow. Correct?

Yes

I'm currently trying to push through as much water as possible because I'm running a pretty large pump. My siphon is fully open. The water level in the overflow is right to the top of the bulkheads, completely covering both downturned elbows. The upturned elbow is sticking out of the water about half an inch. Does this sound right?

Yes

 

[autodave]

Hate to respond to myself before an answer to my first question but I had an idea. If I am keeping flow under 1000 gph could I use some reducers and then a 1" gate valve at the end of my 1.5" drain?

I can try to help. Yes,you will want to put your gate valve inthe basement at the sump,which would make it a 2 person job to adjust.
For a flow under 1000gph you could do all 1 inch for your siphon.

 

[uncleof6]

Yup, the open channel is taking a lot of flow. Pretty much as much as it can without the water rising in the overflow.
I'll probably be downsizing pumps, but was trying to see how much I could open it up.
Is there anything wrong with the siphon channel being fully open?

Sounds to me like your plumbing is too small. Should only be water just flowing in the open channel. It is a small amount, not amounting to over a couple hundred gallons an hour--if that.

 

[uncleof6]

Hate to respond to myself before an answer to my first question but I had an idea. If I am keeping flow under 1000 gph could I use some reducers and then a 1" gate valve at the end of my 1.5" drain?

That seems rather pointless if you ask me. Why add more variables to the system. Keep it the same--top to bottom--set it and forget it.

 

[uncleof6]

Would the BA overflow concept work in a traditional overflow as a replacement for Durso standpipes? My overflows in my 300g tank are drilled for two 1.5" bulkheads and two 1" bulkheads. The overflow box itself is 6" x 18" so there would be enough room for the elbows within the overflow. I would be able to use the required three standpipes and still have a hole left over for my return line. Would it work this way?

Yes, however the siphon and open channel must be in the same overflow. It will not operate properly, if the siphon and open channel are in different overflows. The siphon and open channel need to interact with each other.

This modification has a drawback, however, in that there will be no flow in the second overflow, as it will only contain a dry emergency and returns. Setting it up differently, would add variables that can't be accounted for.

It has been suggested to fill the second overflow with sand for a mini-dsb, however have not done this, and am not sure of the realistic viability of the idea.

 

[d2mini]

Sounds to me like your plumbing is too small. Should only be water just flowing in the open channel. It is a small amount, not amounting to over a couple hundred gallons an hour--if that.

Well, it's more like my pump is too big.
Reeflo barracuda gold.
I normally only run a 3-4x turnover.
I'll probably downsize the pump.

Thanks!

 

[uncleof6]

Well, it's more like my pump is too big.
Reeflo barracuda gold.
I normally only run a 3-4x turnover.
I'll probably downsize the pump.

Thanks!

An antiquated, and misunderstood "follow the leader" rule of thumb, that really is not pertinent to a reef aquarium. You should be up around 10x or better. It is a long dissertation trying to explain why a reef tank, is not run like a tank with an under gravel filter--where this rule of thumb comes from.

 

[Regf]

These are awesome builds, cant wait to do mine!

 

[BeanAnimal]

Reg

Welcome to RC... You will quickly find that posting pointless 1 liners to pad your post count will not get you into the buy/sell forums and it tends to annoy folks


Ataller:
Valve at sump. Reason... You want to avoid cavitation created by the large drop and negative pressure.

d2mini:
If the open channel and emergency standpipes are built the same as the siphon and the siphon IS NOT valved back at all, then they system may not (fully) fail-safe as designed. Why? The current capacity requires the FULL bandwidth of ONE standpipe and the partial bandwidth of another. That said, chances of a full clog in 2 standpipes is not likely but you are right at the edge of the envelope.

 

[d2mini]

An antiquated, and misunderstood "follow the leader" rule of thumb, that really is not pertinent to a reef aquarium. You should be up around 10x or better. It is a long dissertation trying to explain why a reef tank, is not run like a tank with an under gravel filter--where this rule of thumb comes from.

Actually I knew that a lot of flow is more common with reef aquaria, but i've lately chosen to run much less flow through my sump and utilize power heads inside the display for more flow. Just the way I prefer to do it and it works well for my tanks.

Bean, good point. Will throttle back a little on the siphon.

 

[ataller]

Thanks everyone.