Silent and Failsafe Overflow System

[BeanAnimal]

If that where the case then the Herbie design would not work and people have been using it for years.

Many folks who use a single siphon (AKA a "herbie") must often fine tune the system because it can easily get out of balance and start flowing into the "emergency". This may be fine for some folks, but is not what I wanted and did not have a true "fail-safe".

Secondly, most "herbie" systems use full height overflow boxes with somehwat short siphon standpipes. As the water in the box rises, so does the head against the siphon. This does not work well in a coast-to-coast as the balanced tuning point leaves little wiggle room between sucking air or flooding. The "fix" is the open channel and setting the system to a flow rate that is more than the siphon itself can handle.

Lastly, one size fits all was a major part of my design criteria. The goal was a fail-safe system that could be scaled if needed, but built as published would be able to handle from a few hundred GPH to several thousand GPH without changing ANYTHING. one-size-fits-all.

In other words, my design was the result of specific criteria, some of which the "herbie" did not meet. The result is a set and forget system that can be built as published for and used for any reasonable flow rate safely and quietly.

 

[TheFishMan65]

Yes, I agree. But would you say it is required that some water go down the open channel and if so why. That is what started this discussion. I was only trying to explain why I did not think water had to be in the open.

Thanks

 

[BeanAnimal]

If you tune the system so that NO water is entering the open channel, then you have tuned the system to the lowest operating point. If anything causes lower flow (pump calcification over time, change in barrometric pressure, worn impeller, etc) the siphon will begin to suck air.

The open channel allows the system to be tuned to the "middle" of the operating range so that a very wide range of flow fluctuations can be handled by the sytem (no human intervention) with no affect on the system function or balance.

 

[CJBROWN]

And brilliantly done!
I don't suppose many of us would have figured it out on our own. It's silent and failsafe. And adaptable to a wide array of overflow styles and arrangements.
:beer:

Many folks who use a single siphon (AKA a "herbie") must often fine tune the system because it can easily get out of balance and start flowing into the "emergency". This may be fine for some folks, but is not what I wanted and did not have a true "fail-safe".

Secondly, most "herbie" systems use full height overflow boxes with somehwat short siphon standpipes. As the water in the box rises, so does the head against the siphon. This does not work well in a coast-to-coast as the balanced tuning point leaves little wiggle room between sucking air or flooding. The "fix" is the open channel and setting the system to a flow rate that is more than the siphon itself can handle.

Lastly, one size fits all was a major part of my design criteria. The goal was a fail-safe system that could be scaled if needed, but built as published would be able to handle from a few hundred GPH to several thousand GPH without changing ANYTHING. one-size-fits-all.

In other words, my design was the result of specific criteria, some of which the "herbie" did not meet. The result is a set and forget system that can be built as published for and used for any reasonable flow rate safely and quietly.

 

[JTL]

What I understand from this conversation is that the reason for some water going into the open channel is to make sure there is a higher water level in the box than the minimum to maintain a full siphon. I mostly keep my water level 1-2" above the minimum but just not high enough for water to get into the open channel. If I were to raise the water level higher there would not be much of a difference between the tank level and the overflow box level.

 

[CJBROWN]

What I understand from this conversation is that the reason for some water going into the open channel is to make sure there is a higher water level in the box than the minimum to maintain a full siphon. I mostly keep my water level 1-2" above the minimum but just not high enough for water to get into the open channel. If I were to raise the water level higher there would not be much of a difference between the tank level and the overflow box level.

Got some pics of your setup?
Internal box, CC?

Something doesn't sound right there. Sounds like there's a large height difference in your standpipes. Is your open standpipe break-over too high?
How exactly would you raise your water level if you were to do it?
If you have no water flowing thru your open standpipe, how do you balance the flow?

 

[RocketSurgeon]

The open channel allows the system to be tuned to the "middle" of the operating range so that a very wide range of flow fluctuations can be handled by the sytem (no human intervention) with no affect on the system function or balance.

ergo..."Set and Forget".

Thanks Bean.

 

[JTL]

Chris, I have an external box. Water flows over the side of the tank which acts like a weir and collects into an external box. The down turned street els are the same height they are just too high in the box. If I set the water level to flow into the open channel it is almost as high as the tank level. The distance between where water can enter on a full siphon and where it free flows is about 2" I generally am somewhere in between. The water level is set via a gate valve on the full siphon standpipe. You don't even need an open channel for that, but of course then it would not be a Bean design which is what we know and love. I am in the early stages of designing a new tank, probably a 75g that will have an internal box flowing to an external and using a Bean system. I am not sure I will like it as well as a single external box but due to space requirements I have no choice. How is your 75 set up?

 

[CJBROWN]

Chris, I have an external box. Water flows over the side of the tank which acts like a weir and collects into an external box. The down turned street els are the same height they are just too high in the box. If I set the water level to flow into the open channel it is almost as high as the tank level. The distance between where water can enter on a full siphon and where it free flows is about 2" I generally am somewhere in between. The water level is set via a gate valve on the full siphon standpipe. You don't even need an open channel for that, but of course then it would not be a Bean design which is what we know and love. I am in the early stages of designing a new tank, probably a 75g that will have an internal box flowing to an external and using a Bean system. I am not sure I will like it as well as a single external box but due to space requirements I have no choice. How is your 75 set up?

Without seeing it I'm guessing you could adjust the height of your standpipes to get the water level where you want it. Setup and tuned correctly the overflow box water level will run at the centerline of the open standpipe (per BeanAnimal).

Mine is an acrylic with the weir slot cut through the back wall of the tank, external box, 1" BH's and thinwall pvc. Works famously, running about 450gph with an eheim 1260. Here are a few photos of how it got setup:
http://www.reefcentral.com/forums/showthread.php?t=1991450

The build thread I've kept up best with the most detail is on TRT:
http://www.thereeftank.com/forums/f6/new-75-build-coach-needed-budget-build-165347.html

 

[JTL]

Chris, your tank looks nice. I have had acrylic tanks in the past but I always seem to scratch them up. I can even scratch glass with a plastic scraper. Good to know that the 1" pipe is working good.

John

 

[CreativeGuy]

I have been following this thread and trying to implement silent overflows and safety into a new 600g custom tank that has been in fabrication for a couple of months and its final designed of its two rear external coast to coast boxes has to be submitted this month. As it is a complicated set up, I was unsure whether to ask things in this thread, or begin a build thread for the entire project (which is about 1,400g of multiple tanks and 1,600g in a common filtration systems) and ask for input there? The questions or input I am seeking is related to specifics about the design of the overflow boxes, water flow into the boxes, dynamics of multiple gravity discharges (2 separate full siphon ones and a third with a tube for partial), also additionally drawing 4 closed circulation loops and a safety plumbed to the sanitary drain to prevent overflowing the tank. There are two pumped main returns from the filtration system. This is only a basic brief description, as I wished to be respectful of someone else's thread and ask permission before trying to post a lengthy description with multiple CAD and flow drawings, or just to start another thread.

Joe

 

[RocketSurgeon]

Start a new thread so u can have our undivided attention. Edit your post here to add a link so we can easily find it.

 

[dmastracchio]

Hey all,

I just finished my 55 to 180 move. Tank has a custom C2C overflow with the BA system designed. Everything works great when the pump is running and everything is flowing!

Problem 1 is however, when say I turn off the pump, the siphon continues to siphon until it sucks air which then breaks the flow. So now the C2C box is pretty much empty, maybe a 1/2" of water stands in it. Pump turns back on, it begins to fill the box but the siphon does not full commit to siphoning. The open end pipe handles most of the flow so there's no overflow or anything bad, it's just loud again.

I have to unscrew the cap of the siphon to let the flow begin like a normal drain then i re-screw the cap on which turns it back into a siphon again and it resumes normal operation.

Anyone got any ideas maybe?

 

[RocketSurgeon]

Typically the siphon doesn't start because either it is not air tight ( using paste around cap threads?) or it terminates too deep in the sump ( is it below 1/2 inch of water line?)

 

[BeanAnimal]

Joe:

I don't mind the information being presented here as long as it is regarding implementation of this type of overflow system.

 

[BeanAnimal]

Hey all,

I just finished my 55 to 180 move. Tank has a custom C2C overflow with the BA system designed. Everything works great when the pump is running and everything is flowing!

Problem 1 is however, when say I turn off the pump, the siphon continues to siphon until it sucks air which then breaks the flow. So now the C2C box is pretty much empty, maybe a 1/2" of water stands in it. Pump turns back on, it begins to fill the box but the siphon does not full commit to siphoning. The open end pipe handles most of the flow so there's no overflow or anything bad, it's just loud again.

I have to unscrew the cap of the siphon to let the flow begin like a normal drain then i re-screw the cap on which turns it back into a siphon again and it resumes normal operation.

Anyone got any ideas maybe?

As mentioned, the cap must be sealed and the standpipe should not terminate any deeper than an inch (at normal operating level) into the sump. You can drill a small hole in the siphon standpipe just above the sump's normal water line, but it should not really be needed.

Also, thank you for your service.

 

[rad1687]

Is the amount of water flowing through the open channel sufficient to feed to refugium portion of a sump?

 

[BeanAnimal]

In general, no.

Also, in my opinion most folks put far to little flow through their refugia. While I don't grow macro in my sump (or light it) the flow is extremely high. My sump is full of pods, white fan worms, tunicates and sponges. I just took the refugium (above tank) off-line (it was a detritus trap) to redesign it. It was also high flow and full of life.

 

[JTL]

Typically the siphon doesn't start because either it is not air tight ( using paste around cap threads?) or it terminates too deep in the sump ( is it below 1/2 inch of water line?)

That is a problem that I had at one time. I raised the pipe in the sump and re-sealed all of the full siphon connections. It is a lot better but it still takes a couple of minutes to get a full siphon. I have one more 90 on the full siphon than on the open channel and that may make a difference.

 

[JTL]

Is the amount of water flowing through the open channel sufficient to feed to refugium portion of a sump?

Kinda depends on how much flow you have, but I doubt it. Some would say not to feed the fuge from the DT because of detrius build up. I just run mine off the main pump, but at one point I put a small pump in the return chamber.