The Todd Overflow

MidwesternTexan

Average Joe
This is really nothing new, and not really a new design.

Hello all,

This is my version of the BA, and the Herbie combined;

I call it,

"The Todd"

Works like this:
I had bought a 180 with 2 x holes for a 1.5 I.D. Bulkhead already horizontal in a top corner.

I added the C2C overflow myself to the upper back out of glass.

This is silent, has it's own 'emergency' overflow- if/when the water rises in the overflow
the tip of the black hose goes under water turning the Secondary whole in to a full siphon
1.5" drop 9.5ft to my sump beneath.
Normally, this line just trickles down to the sump- taking up the slight extra while the 'primary' line with the gate valve- stays at full siphon.
No matter what the 'primary' line is running- the secondary will always flow- unobstructed down to the sump.
The 'primary' runs at full siphon by restricting the flow to closely almost match the flow of the RP. The rest going down the secondary which also pulls a bit of air into the secondary thru the black tube. Again, if/when the water level rises in the C2C, the black hose goes underwater and turn the 'secondary' into a Full siphon, quickly emptying the C2C.- I"ve of course tested this numerous times by shutting off the 'primary', and it works great, and is silent.
The outer Sanitry 90 is a 1.5" I.D. Fernco Fitting- before you bash it, I even talked to the lead engineer at Fernco- It's Reef Safe!

The Rubber sanitery 90's/3-way also takes all the pressure off the glass/bulkhead!- I know- Damn brilliant idea! Again- others used them too with no problems.



This is my 180


Again,
I did it this way for two main reasons:
1. The 180 I picked up like new already had the 2 x 1.5 I.D. bulkheads drilled in it
2. After reading and getting feedback from others who did it like this- I knew it worked.
 
And, just so nothing that would clog my 1.5" I.D. secondary, or the siphon primary for that matter, I slipped a piece of egg crate in the trough.





This way, it is extremely unlikely that it will clog/overflow the DT top.
 
Nice tank! The over flow looks through to me

Well thanks! It's virtually silent, and has been working great!

When I shut the valve on the primary/siphon line-
all the flow is easily handled by the secondary/open line.

Otherwise the secondary only barely trickles as the self adjust to the
Primary line.
 
I noticed the siphon side taking a long time to purge the air when I'd shut down the return pump during feeds.
I would have to manually block the secondary side, change the valve on the siphon, etc., to finally get it to balance out again and run quiet and on full siphon.

I had the end of the siphon side going about 3 inches underwater where it empties to the skimmer section- which stays constant height anyways.- This was the problem. That little bit extra underwater on the end was keeping it from purging the air easily.

I cut the pipe so it's now about 1/2 inch under.
It now restarts itself, and purges the air in the siphon line in 3 minutes of less without touching anything.

So now I can hit my feed button on my RP, feed frozen/whatever, and let it restart without anymore effort on my part.
Now, the secondary side does not even go to full siphon, and when it purges the air, little is any flow goes thru the secondary side.

Another productive easy fix! Now it's a no touch restart to normal operation again.
 
as failsafe as you like to think that secondary line is, it isn't, and much as you may think nothing will clog either line your wrong…that is the beauty of saltwater tanks…millions of things grow in them…and much of that is stuff you can't see in dark places…many many critters and things like cryptic spaces to grow…sponges, spironoid worms, vermitid snails, various types of algae etc, all enjoy growing in dark zones…it doesn't take as many of these as you would think to hinder the progress of water to a point where the tank overflows…

just a heads up…your tank looks beautiful though…

curious why you didn't just drill another hole and not have to battle life and physics the whole time this tank is running…the weight of flood potential in a tank so large would weigh heavily on me to the point i would have a very hard time leaving my house for any period of time…

why not just leave it as an actual herbie design and have the secondary pipe face upward and not take any water at all eliminating the worry of things growing in a line that is to be used as an emergency…

also the rubber "T" does nothing for eliminating the pressure on the tank, the water weighs what it weighs in the pipes, the rubber "T" likely weighs more then a plastic one would have and it is the weight of the water in the pipes acting as a lever on the bulkhead that stresses the glass, in your case it is a very long lever (9+') to the basement, i have seen what i can do to a welded on nut with a 4' bar, can only imagine the amount of torque that could be generated by a 9' lever.

i don't mean for any of this to come across as condescending either, that is just how things look in text… your tank is beautiful, and i hope all the best for it...
 
I have to agree with Nano. Like you said in your intro, this is essentially a Herbie (with a slight modification, ala Beananimal) If you are running water in it, there's the opportunity for stuff to build up.

The problem actually arises when the secondary train unexpectedly clogs. By design, you have the primary throttled back so it can't quite handle everything and you depend on the secondary to handle the excess. If it should clog for any reason, the excess will build up and cause a flood.

In some ways the Bean-style tubing actually makes things worse - it increases the amount of flow the secondary will handle before is starts gurgling and flushing, delaying any warning to you that something's amiss.

All of this may seem quite unlikely, and it is, but as many people can tell you, unlikely things tend to happen at inopportune times (at least that's what that Murphy guy says!)

I'll also 2nd Nano's comments - your tank is beautiful and I also don't want to be condescending or overly negative, I just want to make sure you (and others reading the post) are aware of the potential drawbacks.
 
Thanks to both of the posts above, for stating your view and opinions- very nicely I might add.

The secondary actually has little, if any flow thru it. I keep the elbow turned down- so it doesn't make any noise. The secondary line has a air line- which goes under water if the overflow level rises near the top- and turning it into an instant siphon of 1.5" line- no obstructions.

I had an intank overflow- DIY, over the top style that was 1.5" and worked great on my 125g (now my sump) and nothing ever 'grew' in that dark pipe, etc. for almost 3 years.

You may have missed that I bought the 180 used with 2 holes drilled near the top and added my coast to coast overflow to it.
I was going to drill a 3rd hole, and several people PM'd me and stated they were basically doing it the way I am with the 2 holes- and no problems.
So- I decided not to drill the third hole- and while it would be nice to have a 3rd emergency- I'm glad I didn't attempt it.

My Overflow system is truely:
full length surface skimming
silent
set it and forget it

And yes, I do understand the differences in the 3 vs 2 systems, and YES
3 has more redundancy for preventing an overflowed DT.

So yes, the 3 drains is better.
When done correctly, 2 also works well and is no real danger.
 
One thing I'm not sure about, if I dump some extra water into my tank with a herbie the emergency line lets everyone in the room know it's taking on water with a loud gurgling. Are you going to get that with this set-up letting you know that you need to adjust your full syphon line?
 
One thing I'm not sure about, if I dump some extra water into my tank with a herbie the emergency line lets everyone in the room know it's taking on water with a loud gurgling. Are you going to get that with this set-up letting you know that you need to adjust your full syphon line?

No, and personally I like it the way I have it.
I often glance at the side of my C2C overflow, notice the level in it, etc.
At my daily sump look, I'd notice if the secondary is running- cause it pulls bubbles with it and you can see them in the return section.

It's pretty much set it and forget it.

Before, when I powered off the RP for feeds, it would take a long time to run right again, and I would usually mess with the returns to get the siphon to clear air, etc.- wasn't good.
So- I made the far end in the sump return section about 1/2"underwater, whereas it was about 3".
This cleared up everything! Now, power back on the RP- and do nothing- and the siphon clears and gets quiet in literally 3 minutes or less- without touching a thing! It's so nice.

Set it and forget it.
 
There are 2 main keys to these systems running quietly. First, they main drain has to be a full siphon with no air in the pipe. To accomplish this without intervention each time, the discharge of the main siphon needs to be close to the surface. As Todd discovered, if it's too far below the surface, it will prevent the all air from being discharged, or take an inordinately long time to do so.

The second requirement is that the 2nd channel is running at a low enough volume so that it doesn't gurgle. The amount that this pipe can handle depends on the size of the pipe but ultimately determines the silent 'bandwidth' of the system, or range of flows over which it will remain silent. The extra tube that Bean added to his system and Todd has adopted essentially converts this drain into a Durso, letting it handle more flow without gurgling; hence the ability to 'set it and forget it;' the range of silent flow that the second drain can handle quietly compensates for the inherent instability of the full siphon.

If the flow in the secondary drain exceeds its capacity it will begin to gurgle. One of the significant modifications that Bean made was to position the air tube for the second Durso-style pipe so that it would be occluded if the tank water level increased above a certain level. This prevents air from being entrained and instantly puts the flow in the pipe above it's capacity to flow silently; it then converts to a full siphon and rapidly drains the water level down until air can enter the tube again, hence the 'flushing' Bean mentioned.

John08007 - You asked if adding extra water to the tank would affect the noise of the system. It's important to realize that the noise is caused by the extra flow in the pipe. When you add extra water, there is a transient increase in flow as that water is transferred down to the sump. If that increase in flow exceeds the 2nd pipe's silent capacity it will gurgle, as I described above. That will be true for a Herbie, A Bean or a 'todd.' After the water as drained down, the actual flow will be the same and it should return to it's baseline.
 
i would say the two main things to making these systems run properly and failsafe is full siphon, and DRY emergency…

the secondary line is primarily there to accommodate changes in water levels caused by head pressure and barometric pressure changes…in a perfect world with no ambient pressure changes, no evaporation, and nothing growing in the pipes there would be no need for a secondary line and the siphon would always handle the flow as the day it did it was first setup…

however all the above changes happen regularly and continually in our systems…

the herbie system is designed to run consistent and quite every time with a little bit of intervention…i.e., you have to maintain water levels through top off, there is little anyone can do about barometric pressure though, and you have to keep your pipes clean…that done, the water levels are going to fluctuate in the overflow box moderately day to day hour to hour…nothing else you can do about it…

with the bean system the secondary pipe maintains a perfect level in the overflow box by accepting the tiny bit of fluctuations, therefore eliminating the need to constant monitor your water levels..

the one thing both systems have in common is a DRY emergency drain line…this line is to ONLY take water if a problem should arise with the main drains..the outlet for this drain should be above the water line in the sump as well to create splashing and an audible warning that something is amiss…

to butcher or setup either system in any other way is kind foolish…they work perfectly fine the way they are designed…and by design do not work as promised should you deviate from proper implementation..

It has been said in every single post referring to these two setups that you should NOT operate a full siphon drain system without the use of a DRY emergency back up…to do so is asking for trouble...
 
The sleep Doc said:
'If the flow in the secondary drain exceeds its capacity it will begin to gurgle. One of the significant modifications that Bean made was to position the air tube for the second Durso-style pipe so that it would be occluded if the tank water level increased above a certain level. This prevents air from being entrained and instantly puts the flow in the pipe above it's capacity to flow silently; it then converts to a full siphon and rapidly drains the water level down until air can enter the tube again, hence the 'flushing' Bean mentioned.'

Did you see my explanation, and the pictures of my 'secondary'- that is similar the the 'Beans' method? I looked again- First post.
It's the small black hose- that ends in the overflow, neat the top;
That- if the level in the overflow rose that high- it turns that into a FULL siphon-UNobstructed(no gate valves) flow to the sump.
Another reefer came over today, and as usual, commented:
'this thing is silent!' I just smile.

Again- like I said, I bought this 180 with the two holes for 1.5" bulkheads already in it. Was going to drill a 3rd, but several people told me about a system like I'm running, and how the 3rd line is a bit overkill and they never had a problem.
Now if you use smaller diameter secondary- that on full siphon would still barely flow enough- you might have a problem.





i would say the two main things to making these systems run properly and failsafe is full siphon, and DRY emergency"¦

the secondary line is primarily there to accommodate changes in water levels caused by head pressure and barometric pressure changes"¦in a perfect world with no ambient pressure changes, no evaporation, and nothing growing in the pipes there would be no need for a secondary line and the siphon would always handle the flow as the day it did it was first setup"¦

however all the above changes happen regularly and continually in our systems"¦

the herbie system is designed to run consistent and quite every time with a little bit of intervention"¦i.e., you have to maintain water levels through top off, there is little anyone can do about barometric pressure though, and you have to keep your pipes clean"¦that done, the water levels are going to fluctuate in the overflow box moderately day to day hour to hour"¦nothing else you can do about it"¦

with the bean system the secondary pipe maintains a perfect level in the overflow box by accepting the tiny bit of fluctuations, therefore eliminating the need to constant monitor your water levels..

the one thing both systems have in common is a DRY emergency drain line"¦this line is to ONLY take water if a problem should arise with the main drains..the outlet for this drain should be above the water line in the sump as well to create splashing and an audible warning that something is amiss"¦

to butcher or setup either system in any other way is kind foolish"¦they work perfectly fine the way they are designed"¦and by design do not work as promised should you deviate from proper implementation..

It has been said in every single post referring to these two setups that you should NOT operate a full siphon drain system without the use of a DRY emergency back up"¦to do so is asking for trouble...

Essentially, my secondary/back up operates like a dry emergency drain. It also takes a scant amount of excess in the overflow that does not go down the siphon primary. When I shut the primary down completely, the secondary barely goes to full siphon, handling the FP output nicely.
When I cover the secondary intake while the primary is shut down, the overflow goes near the top, and the air vent intake line goes under the water level- and it creates a full siphoning- straight shot 1.5" diameter line with a 1.5ft drop to my sump. Quickly handles all flow of the RP, without overflowing onto my Family Room floor.

So be it. You think I'm asking for trouble, and I say/think/state that the way my system works- it simply is not.
 
When I cover the secondary intake while the primary is shut down, the overflow goes near the top, and the air vent intake line goes under the water level- and it creates a full siphoning- straight shot 1.5" diameter line with a 1.5ft drop to my sump. Quickly handles all flow of the RP, without overflowing onto my Family Room floor..

This makes no sense - you have 2 pipes. You've closed the valve on one and occluded the other. From your description, the only route to your sump if you do this would be the black durso tubing, unless there is a 3rd pipe I'm not aware of.

Did you see my explanation, and the pictures of my 'secondary'- that is similar the the 'Beans' method? I looked again- First post.
It's the small black hose- that ends in the overflow, neat the top;
That- if the level in the overflow rose that high- it turns that into a FULL siphon-UNobstructed(no gate valves) flow to the sump.

Yup. I saw it. And commented on it in my first post. The post you quoted was meant more as a general explanation of the mechanics of the Bean and Herbie systems than specific commentary on your system. Again, as I explained above, the large range of silent flows that the Bean/Durso setup on the second pipe allows is both what keeps your system quiet and is also it's achilles heel. The fact that you are running water through it means snails, algae, or who knows what can get into the pipe, reducing it's capacity. That obstruction would likely go unnoticed because it has enough excess capacity until something catastrophic happened. You correctly state that the secondary drain needs to be larger than the primary. However it's functional capacity my be smaller than you realize due to unrecognized obstruction. If the functional capacity is reduced below your return pump flow, you have a time bomb.

As I also explained above, the other concern is what will happen if the secondary drain gets clogged or obstructed. Since you are depending on that pipe to handle an unknown portion of the flow, occlusion will necessarily lead to a flood. If you truly have just a trickle this is unlikely to happen, but unless you are monitoring the flow of the secondary drain (which kind of defeats the purpose of a 'set it and forget it' system, the flow can dramatically increase without any sign.

Are these scenarios likely to happen? No. But they have happened, and that is my point. Overkill is a matter of perspective. If your secondary pipe never gets occluded and you never have a flood, a 3rd pipe is overkill. If it does and the third pipe saves your livingroom, it's foresight. Whether it's silent or not, or is functioning as you have it configured is irrelevant, it's a matter of the margin of safety built into the system. You are obviously comfortable with the system as you have it designed. My primary concern is that you seem to be making it out to be safer and more fail-safe than it actually is.
 
Just to clear a few things up. The durso on the BA system is not what makes it silent, in fact it has little if anything to do with the silence or otherwise of the system. The durso, makes the system stable, (self adjusting,) gives the system the very wide bandwidth of flows, but will not necessarily keep it quiet, within that bandwidth.

What makes the system silent, is that the main drain runs in "siphon" mode, e.g. there is no air in the line. Air is what causes the noise in a durso, as it mixes with the water, (turbulence) if the flow is above its laminar flow rate (pipe more than 1/4 full of water.) The open channel (durso) far below the laminar flow limit, so it is also silent and bubble free.

The Herbie is silent, without the durso. It is silent for the same reason the BA is silent. What the herbie lacks, and never had, was the self adjustment feature, which was erroneously added to the Herbie sometime after Bean published his design.

The safety issues that this modification raises, have been well covered in a hundred different threads. Just because people do it, SAY they have never had a flood, or the statistical probabilities, does not make the system safe in any way.
 
This makes no sense - you have 2 pipes. You've closed the valve on one and occluded the other. From your description, the only route to your sump if you do this would be the black durso tubing, unless there is a 3rd pipe I'm not aware of."

Well, I obviously took my fingers off the intake of the secondary, with the primary gate valve closed. The resulting siphon quickly- within seconds- empties the overflow.

I'm using a DC1200- with about 10ft of head height.-It's good flow, but the secondary, siphon or not, can easily handle the flow.

The Uncle of said:
"The Herbie is silent, without the durso. It is silent for the same reason the BA is silent. What the herbie lacks, and never had, was the self adjustment feature, which was erroneously added to the Herbie sometime after Bean published his design."

When I 'set it and forget it'- the gate valve adhjustment that is- if any flow goes thru the secondary AFTER the primary runs at full siphon-(which literally takes less than 3 minutes from feeding shutting down the RP), it is merely a trickle at best. It remains silent after the feeding power out siphon clears.


I'll say it again- in a perfect world- if/when you have 3 drains set up like the BA;
YES- that redundancy is superior! YES!

I never actually read or saw the thread on this Herbie; but I heard about it and used critical thinking. That's why I dubbed mine 'The Todd Overflow'-
my name is Todd.

Todays pic, Iphone 4, sitting in my recliner:

 
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I would have left this as a herbie.
Having the upturned elbow with NO water going through it.
This way you are guaranteed that the secondary will always handle all the water that the primary is handling currently.
And as someone else said, when you start to hear noise, you know water is flowing down the secondary, meaning something is clogging the primary or at least your flow has changed for some reason. It's an audible alarm that something is amiss. You deleted your alarm.

I've run both and would definitely run either of them as they were originally designed, but I wouldn't run the Todd combo. ;) Again, just a friendly warning/my 2 cents. :)
 
I would have left this as a herbie.
Having the upturned elbow with NO water going through it.
This way you are guaranteed that the secondary will always handle all the water that the primary is handling currently.
And as someone else said, when you start to hear noise, you know water is flowing down the secondary, meaning something is clogging the primary or at least your flow has changed for some reason. It's an audible alarm that something is amiss. You deleted your alarm.

I've run both and would definitely run either of them as they were originally designed, but I wouldn't run the Todd combo. ;) Again, just a friendly warning/my 2 cents. :)

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.
 
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.
 
as failsafe as you like to think that secondary line is, it isn't, and much as you may think nothing will clog either line your wrong"¦that is the beauty of saltwater tanks"¦millions of things grow in them"¦and much of that is stuff you can't see in dark places"¦many many critters and things like cryptic spaces to grow"¦sponges, spironoid worms, vermitid snails, various types of algae etc, all enjoy growing in dark zones"¦it doesn't take as many of these as you would think to hinder the progress of water to a point where the tank overflows"¦

just a heads up"¦your tank looks beautiful though"¦

curious why you didn't just drill another hole and not have to battle life and physics the whole time this tank is running"¦the weight of flood potential in a tank so large would weigh heavily on me to the point i would have a very hard time leaving my house for any period of time"¦

I had to wait to reply to this. As I stated, I bought it with 2 holes for 1.5" bulkheads already there. I 180 likke new- NO scrathes, etc. If I thought I needed it, I would have drilled a 3rd hole, in fact I was going to, but got convinced I didn't need it for the reasons I've stated.

why not just leave it as an actual herbie design and have the secondary pipe face upward and not take any water at all eliminating the worry of things growing in a line that is to be used as an emergency"¦

Because it seems to work better/quieter truned downwards- it does has the air vent line.

also the rubber "T" does nothing for eliminating the pressure on the tank, the water weighs what it weighs in the pipes, the rubber "T" likely weighs more then a plastic one would have and it is the weight of the water in the pipes acting as a lever on the bulkhead that stresses the glass, in your case it is a very long lever (9+') to the basement, i have seen what i can do to a welded on nut with a 4' bar, can only imagine the amount of torque that could be generated by a 9' lever.

While I'm not an engineer, of physicist by trade- I do have a Masters in Biomechanics.
I really have to essentially disagree with you on most of this.
First- yes water/pvc pipe weighs what it weighs.
The difference of the weight of the rubber Fernco fitting and a rigid PVC is neglibable- however, although the majority of the weight is supported by the floor with a tightly driven wedge against the PVC-
ANY shock/movement in that pipe is absorbed by the rubber fitting, and NOT the bulkhead itself(which is likely to crack under loads/forces before the glass tank would.) Also, drilling the hole in the glass is another potential cracking point under shearing type stresses. I didn't drill the holes- but the edges were not flat/square with alot of shipping at the surface.
I was able to get the bulkheads to seal anyways without any silicone or sealant.


i don't mean for any of this to come across as condescending either, that is just how things look in text"¦ your tank is beautiful, and i hope all the best for it...

Again, I appreciate that last paragraph, and feel the same way towards you- and I do see the merit in the concerns you pointed out.
 
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