The Todd Overflow

[MidwesternTexan]

Yes, you already said it's silent. I think we all got that.
And I've dealt with both systems more than you know.

Let's say your primary drain is a 100% siphon.
And let's say your secondary is only draining 15% additional.
If your primary clogs, how is your secondary going to handle 115% flow?

And how is it that this works better than the Herbie?
This is a serious question. I'm not ragging on you. I'm just not understanding where the improvement is.

Well thanks, and I'm glad you got that it's silent.
And I do realize that you and many others have a great deal of experience with all types of overflow designs, etc.

Yes, the primary is at 100% siphon.
The secondary is probably less the 5%.
And yes, sorry you missed that when I completely close the primary(and I've done this numerous times);
The Secondary handles 100% of the flow. ( I know you meant that since it couldn't be 115% of the total flow)
It handles it easily.
If the water level in the overflow rises- (in this case- as in completely shutting down the primary) it sometimes goes high enough so the that air vent line goes under the water level, cutting off the vent air, and now the secondary is-
yep you guessed it- a complete, 1.5" diameter, completely unobstructed drop to the sump.
In fact, if the secondary does go to a siphon, it quickly drains down, the air vent vents air in again, and it STILL handles the flow without going back to rising high enough to start the siphon again.

NOw that I have the it set right- for the last few weeks,
about once a day, I shut down the RP so that no food will go over the C2C overflow during feeding.
~ 10 minutes later- my trusty DC12000 ramps up again automatically- coming out of 'feed mode' and the primary/siphon side quickly expells the air and gets silent- within 2-3 minutes- I timed it.
All that without touching any valves, elbows, etc.

I could be wrong, but the Herbie is actually used on a slightly different type system than my overflow style. I'm not an expert on the Herbie, or any others (well, maybe except 'The Todd').

I think it's better because, it's mine

It works and works great.
I'm very happy with my true C2C overflow, and the silent operation of it.

Todd

 

[uncleof6]

Go ahead and run the primary, with the 5% in the "secondary", then without changing any of the settings: block the secondary... you will find the secondary won't drain anything anymore, the air vent tube will be totally useless, and that water will need somewhere to go: it will go on the floor. It is really a rather simple concept. Can't happen? Can't happen in a hundred years? Well evidently as those with more experience point out, it has happened, and this hobby has not been in existance (as it is known today) for much over 58 years, so the odds are not really in your favor. I run a couple hundred BA systems and I have seen the open channel fully occlude more than once. That just in the last 6 years... so the odds are even more not in your favor.

The system works for you. That is all that really matters, in the end. The problem is, that others that have little experience read these threads also, and don't read the main threads. It is important that there be information available for them to make a decision based on the whole story. Basically that is: the system works, it is silent, people use it, in one format or another (with flow in the DRY emergency,) but that does not make it safe, or an advisable thing to do, based on a very wide spectrum of experience, and one very simple rule: never run a siphon without a DRY emergency. There is absolutely nothing personal about it.

 

[sleepydoc]

the majority of the weight is supported by the floor with a tightly driven wedge against the PVC-

That's a crucial point that wasn't mentioned in your original post. The rubber sanitary Tees will do a great job of reducing transmitted vibrations, but they will not reduce the stress. (if unsupported, they they may in fact make it worse by taking what would normally be an almost strictly vertical force and adding an angular component to it.) The only way to reduce the stress is to properly support the pipes so their weight is borne by the support, not the bulkhead or tank. This is key with all plumbing - improper or inadequate support puts you at risk for cracked and leaking joints.

For those interested, the original Herbie method is discussed here. Herbie first devised it in a corner flow with two holes and a dry secondary standpipe. People later started modifying the concept and running a trickle down the secondary pipe. This makes adjustment easier by giving a wider range of silent flows but compromises safety as described above. The "Todd" just applies part of the Beananimal setup to this modification.

 

[MidwesternTexan]

Go ahead and run the primary, with the 5% in the "secondary", then without changing any of the settings: block the secondary... you will find the secondary won't drain anything anymore, the air vent tube will be totally useless, and that water will need somewhere to go: it will go on the floor. It is really a rather simple concept. Can't happen? Can't happen in a hundred years? Well evidently as those with more experience point out, it has happened, and this hobby has not been in existance (as it is known today) for much over 58 years, so the odds are not really in your favor. I run a couple hundred BA systems and I have seen the open channel fully occlude more than once. That just in the last 6 years... so the odds are even more not in your favor.

The system works for you. That is all that really matters, in the end. The problem is, that others that have little experience read these threads also, and don't read the main threads. It is important that there be information available for them to make a decision based on the whole story. Basically that is: the system works, it is silent, people use it, in one format or another (with flow in the DRY emergency,) but that does not make it safe, or an advisable thing to do, based on a very wide spectrum of experience, and one very simple rule: never run a siphon without a DRY emergency. There is absolutely nothing personal about it.

Yes, and thank you again.
You'll remember that I attempted to use references to the BA and Herbie systems- so as not to steer nuebies in the wrong direction.
For the reasons that you state, that's why I also have an eggcrate shield/strainer before the intakes. By my design, very little water flows over the intake end of my C2C- so as to keep the dlow going down the trough.
A larger fish could in fact jump over the area after the strainer in the trough and totally plug the secondary line- it COULD happen. Not likely however. Uncle, I totally agree with you on your worst case scenario, and I always have. If a dry emergency is dry, then you would also agree there is an ever so slight chance that in a worse case scenario- it could become clogged with something too!
I stated many times, the 3 hole system does offer more 'back up' than the method I"m using.

That's a crucial point that wasn't mentioned in your original post. The rubber sanitary Tees will do a great job of reducing transmitted vibrations, but they will not reduce the stress. (if unsupported, they they may in fact make it worse by taking what would normally be an almost strictly vertical force and adding an angular component to it.) The only way to reduce the stress is to properly support the pipes so their weight is borne by the support, not the bulkhead or tank. This is key with all plumbing - improper or inadequate support puts you at risk for cracked and leaking joints.

For those interested, the original Herbie method is discussed here. Herbie first devised it in a corner flow with two holes and a dry secondary standpipe. People later started modifying the concept and running a trickle down the secondary pipe. This makes adjustment easier by giving a wider range of silent flows but compromises safety as described above. The "Todd" just applies part of the Beananimal setup to this modification.

Thanks Doc, an anesthesiologist I assume by your screenname? I'm and ER PA.
And thanks for your explanation above, I thought that's what I've been saying.

 

[MidwesternTexan]

Oh, and btw, I think I may have mentioned this but,
I was using a really nice, DIY Intank overflow that was a HOB style- you know, the one where you have to initially start the siphon by evacuating the air from the inner top loop.
After that- it worked flawlessly for years. I had a high water level in my DT that would shut down the RP- preventing a flood if it lost siphon- it never did.

It was 1.5", DIY- I have a thread(s) on it with pics,
Anyways, my point is this:

After 2+ years- there was virtually now grow in the pipe- I think being completely dark inside helps that.

 

[radiata]

Any idea what the life expectancy of the rubber fittings is in salt water? You could have an accident waiting to happen. I used to use rubber bands to hold nori on to a cleaning magnet - but the rubber bands only last a few weeks in salt water. I switched to silicon bands and they last over a year. (The silicon bands seem to fail after an urchin has made several passes over it while going after the nori.)

 

[BeanAnimal]

I guess then you never look at your system much.
If my secondary- with the elbow turned down- yep it's silent- WILL handle all my flow IF the primary somehow clogged completley-( I can't remember when Hell froze over last) for what- weeks, months, eternity- the air vent will make a slight sound when you get near it.

For my system- this works better than the Herbie ever dreamed it did.

Todd,

Your "system" is a Herbie any way you slice or dice it. Adding the airline fail-safe from the design I published does not change the dynamics of the second standpipe as relates to the original Herbie. You are running a "wet" Herbie and as such inherit all of the risks and design limitations (acceptable or not) of that system. It certainly may be safe enough for you, but it is not a new design. Forgive me for being so forward (I really am not trying to be a jerk), but your posts in my thread and here appear to be more geared toward making a name for yourself more than anything else. That in itself is not bad, but you appear to be presenting the ideas of other's pretty much "as-is" in the context that you have improved upon them in some novel way.

In any case you may be missing some salient points regarding standpipes. If we examine the "Herbie" intake and compare it to "Durso" there is a difference. The Durso intake is submerged so air must be let in somewhere else to control the flow rate (or allow it to run open channel). Without the air intake the Durso (with its submerged intake) will simply siphon and flush. On the other hand, the Herbie intake is open to the air and this prevents it from siphoning and flushing under normal conditions. So far so good, we know how they differ in normal operation.

In operation, if the "Herbie" secondary intake becomes overwhelmed it will become submerged (chocking off the air) and begin to siphon and flush. However, if a Durso becomes overwhelmed it will continue to suck in air through the valve. The air being sucked in will restrict the maximum flow rate (flushing or not) by preventing a full siphon. So far so good, now we know how the both react when overwhelmed.

That brings us to the system that I published. If you read the Herbie thread, I was not (at all) thrilled with the dynamics of the tuned siphon unless it was backed up by a dry emergency (at the very least). The problem with that system is the limited bandwidth and need for constant adjustment. The wet secondary fixes this but at the expense of safety. If that wet secondary is OPEN ENDED then it will amplify the sound of the water flowing through it. That brings us full circle to the down turned (submerged) intake. It is there to prevent noise but that means that air has to be let in somewhere else. If It is open top like a Durso, then there is no fail-safe if it is overwhelmed. I added the airline to work around the issue and regain the safety of the standpipe...

So, as several folks have tried to point out, your "system" is a wet (less safe than a dry) Herbie...

 

[sleepydoc]

Any idea what the life expectancy of the rubber fittings is in salt water? You could have an accident waiting to happen. I used to use rubber bands to hold nori on to a cleaning magnet - but the rubber bands only last a few weeks in salt water. I switched to silicon bands and they last over a year. (The silicon bands seem to fail after an urchin has made several passes over it while going after the nori.)

The 'rubber' in rubber bands is a very different material from the material used for flexible fittings. As long as the metal clamps holding them in place don't corrode they should be fine.

Bean-
Thanks for your thorough (as always) explanation of the physics of the drain systems.

 

[MidwesternTexan]

Todd,

Your "system" is a Herbie any way you slice or dice it. Adding the airline fail-safe from the design I published does not change the dynamics of the second standpipe as relates to the original Herbie. You are running a "wet" Herbie and as such inherit all of the risks and design limitations (acceptable or not) of that system. It certainly may be safe enough for you, but it is not a new design. Forgive me for being so forward (I really am not trying to be a jerk), but your posts in my thread and here appear to be more geared toward making a name for yourself more than anything else. That in itself is not bad, but you appear to be presenting the ideas of other's pretty much "as-is" in the context that you have improved upon them in some novel way.

In any case you may be missing some salient points regarding standpipes. If we examine the "Herbie" intake and compare it to "Durso" there is a difference. The Durso intake is submerged so air must be let in somewhere else to control the flow rate (or allow it to run open channel). Without the air intake the Durso (with its submerged intake) will simply siphon and flush. On the other hand, the Herbie intake is open to the air and this prevents it from siphoning and flushing under normal conditions. So far so good, we know how they differ in normal operation.

In operation, if the "Herbie" secondary intake becomes overwhelmed it will become submerged (chocking off the air) and begin to siphon and flush. However, if a Durso becomes overwhelmed it will continue to suck in air through the valve. The air being sucked in will restrict the maximum flow rate (flushing or not) by preventing a full siphon. So far so good, now we know how the both react when overwhelmed.

That brings us to the system that I published. If you read the Herbie thread, I was not (at all) thrilled with the dynamics of the tuned siphon unless it was backed up by a dry emergency (at the very least). The problem with that system is the limited bandwidth and need for constant adjustment. The wet secondary fixes this but at the expense of safety. If that wet secondary is OPEN ENDED then it will amplify the sound of the water flowing through it. That brings us full circle to the down turned (submerged) intake. It is there to prevent noise but that means that air has to be let in somewhere else. If It is open top like a Durso, then there is no fail-safe if it is overwhelmed. I added the airline to work around the issue and regain the safety of the standpipe...

So, as several folks have tried to point out, your "system" is a wet (less safe than a dry) Herbie...

BA,

Thanks for pointing out what has essentially been pointed out-
but-
-Herbies system was/is for using the holes predrilled in a RR tank- right?
-He re-vamped it, used the hole meant for a return, and used it as a drain of some type- right?
Have I ever mentioned doing this, or that this could be done on a 'bottom predrilled' tank?
I needed a system that worked well, certainly well enough for me, my system, my family room in my home, etc.
No one will be more famous than you, and your overflow.
Thanks to yours, and Herbies, I came up with mine.
I didn't read his whole thread, I think only the OP.- While it only uses 2 drains like his vertical standpipes, and essentially is quite similar- well, never mind.

There are standpipes, with all kinds of 'gurgle busters', dursos, etc. put on top of them, including what Herbie did by adding several holes in the side of a standpipe- right?
-Does the BA use 'standpipes'??

Are you somehow forgetting that my secondary does indeed have the air vent, that does indeed 'become clogged'(when it submerges)?

Mine is most similar to the BA- without the 3rd emergency.

Have I ever denied this? Have I ever said that somehow without the 3rd emergency drain- it was somehow better?
Can we continue to beat this dead horse?

:deadhorse1::deadhorse1::deadhorse1:?

You may or may not be happy to know, that when locals are doing a build, with various kinds of DIY overflow drilled near the top,
I always suggest and advocate:
A thinner C2C overflow
At least 2 large holes drilled in the back/side(peninsula style)
A box on the back with: wait for it......................
3 holes drilled and used as a BA style overflow

I'm actually not much of a jerk either, and certainly never thought you were.
Thanks for adding your input on this thread.

 

[MidwesternTexan]

The 'rubber' in rubber bands is a very different material from the material used for flexible fittings. As long as the metal clamps holding them in place don't corrode they should be fine.

I spoke with the Lead Technician at the Manufacturer- Ferco fittings
and after a long discussion- we both determined that this is a suitable use for this fitting.
The metal clamps ( I could have used plastic Zip Ties), never get wet, and this far, show zero oxidizing/corrosion.
I also conversed via PM's with several people who used these fittings on their marine tanks- all positive for years.

If you think about it, the SW is almost like RO compared to what these fitting are designed to have flow thru them :lolspin:

 

[d2mini]

but your posts in my thread and here appear to be more geared toward making a name for yourself more than anything else.

You picked up on that too, eh? :lol:

 

[MidwesternTexan]

A name for my self? I already have one, but thanks.

I call the next one the 'Dennis from Texas'....:beer:

 

[BeanAnimal]

BA,

Thanks for pointing out what has essentially been pointed out-
but-
-Herbies system was/is for using the holes predrilled in a RR tank- right?
-He re-vamped it, used the hole meant for a return, and used it as a drain of some type- right?

You are attempting to define the "herbie" by describing its physical appearance, not its hydraulic operating properties. Changing where the standpipe penetrates the tank or the fittings used does not necessarily change the operating principal or parameters.

Happy Thanksgiving

 

[MidwesternTexan]

You are attempting to define the "herbie" by describing its physical appearance, not its hydraulic operating properties. Changing where the standpipe penetrates the tank or the fittings used does not necessarily change the operating principal or parameters.

Happy Thanksgiving

Totally agreed.

I think you mentioned that the Herbie needs, of needed constant adjustment of the 'siphon' line. I'm assuming this would keep the secondary dry if not needed.

On your system, you utilize the secondary to keep it self adjusting and to rarely ever have to adjust the siphon line.
And a 3rd line was added to boot.
Great design- and as I said.

I feel my version is therefore more like yours- without the 3rd drain.
I rarely ever adjust my siphon.

At this point, it's a matter of statistical probability-
- If the primary fails/clogs and
- if the secondary fails/clogs (then Mine would have a problem)
- and if the 3rd drain failed/clogged with the other 2-(yours would have a problem)
- and, if another line failed/clogged- and so on

You have probably read the Herbie thread perhaps more than I.

My version is basically the same as yours, without the 3rd drain.
Again, I didn't wan't to drill my already drilled tank to add the 3rd, and settled on this system that is silent, hands off, and works great.

Happy Turkey Day to you too sir

 

[BeanAnimal]

Totally agreed.

I think you mentioned that the Herbie needs, of needed constant adjustment of the 'siphon' line. I'm assuming this would keep the secondary dry if not needed.

In general, yes. Thus the need/reason/desire to run the second pipe WET for stability reasons, as published in my design. One of the drawbacks of running the second pipe wet in a herbie is (again) the loss of a true standby fail-safe. That said, many folks assume the risk as acceptable and do it anyway. There have been many rather inflamed arguments on the topic over the years.

I feel my version is therefore more like yours- without the 3rd drain.

a Herbie

As for failure probability, there is a lot more to it than that. There are design less likely to fail or quieter or capable of more flow or any other number of design parameters. My comments are not in context to what is better or worse, or for that matter what is more applicable or suitable for a given situation.

If, given your system parameters, a wet herbie offers you the safety, stability and silence you are comfortable with, then that is all that matters. Call it "The Todd" if you wish, but it is a Herbie by function.

 

[sleepydoc]

The metal clamps ( I could have used plastic Zip Ties)

Plastic zip ties would be a very bad idea for this - rubber fittings are held on solely by friction. A metal clamp allows one to get the fitting quite snug and therefore have a lot of friction. Plastic zip ties are more difficult to get snug and will not get as tight as a metal clamp. In the pics posted one can see that the rubber fittings have deformed slightly, indicating that there is stress on them. Given the fact that hundreds of gallons an hour are flowing through the fittings, metal clamps are the only good choice.

As for failure probability, there is a lot more to it than that.

+1

 

[MidwesternTexan]

I"ve been working alot lately- thank God; but I find time to 'tinker' with the system.

A few weeks ago, my CB Angel took a ride to the sump, and is now in the frag/RP area. In a few weeks I"ll do a WC and take stuff out so as I can retrieve him.

But, finally, so it doesn't happen again, I fashioned a grill for my Coast to Coast overflow.
It was quick and easy, free, and easy comes out when cleaning is needed.
As always, here's some pics







I'm still keeping the grille just before the drains- although the CB Angel did manage to push it over and get down the drains- hence the grille on the C2C

 

[d2mini]

I'm sure the egg crate works well for preventing fish from flowing over, but an even better solution if you can manage it is to build a removable acrylic cover. This will keep algae from growing inside your overflow from all that light it currently receives. I've been there.

 

[FraggledRock]

You're missing an emergency drain. And egg crate isnt as failsafe as you hope. Plus a vslve makes your drain hole smaller. Adding another level of worry...

Good luck looks good!

 

[BeanAnimal]

I used egg crate for several years in an attempt to keep my shrimp from taking the ride to the sump. It became a very attractive place for macro to accumulate and grow and it also somewhat impeded surface skimming. The egg crate was used instead of covers due to the multiple over the top returns covering portions of the overflow box (oceans motions). I have long since re-plumbed the returns and now have fitted covers that leave on a slot above the weir. No more macro in the overflow and now more shrimp or snails in the sump!