View Full Version : Herbie Clog - Why?
jeremyjoslin
03/03/2013, 01:40 AM
I've been running a herbie setup with emergency float switch for about the last 6 weeks with no problem until tonight.
Background: 300g DT with 1.5" siphon tuned by gate valve, 1.5" open pipe with trickle running through it, and a float switch set so that if water level goes above emergency drain (even by anything more that a trickle) the return pump will turn off and an email alert gets sent to me via Apex. After 30 seconds, the return pump will turn back on thus giving some small boluses of warm, oxygenated water from the sump.
Tonight while at work (overnight shift), I got an email alert for high water level in DT. Called my wife who went downstairs to take a look. Sure enough, the siphon line couldn't handle the flow, and the water level was rising above the emergency line enough to trigger the switch. I had her open the gate valve all the way, and it's now draining fine. I'll keep it fully open overnight until I can get home in the morning and re-tune.
I just can't imagine why the siphon clogged all of a sudden. I have a strainer over the start of the siphon line and nothing was clogging it there. Seems it just needed to be flushed. This makes me nervous....
Has this happened to anyone else? Should I be flushing the line regularly? This hadn't come to mind until this happened tonight and I started searching. My scenario doesn't seem to be common though (or just not reported).
Thoughts or suggestions?
The Punisher
03/03/2013, 01:53 AM
Mine does the same thing from time to time. I've had a clump of bubble algae as well as small snails get through the strainer and even a tiny snail in the gate valve can be enough to raise the water level a little bit. I recently had to remove the piping under the tank to remove my sump and I looked in the gate valve at the position I normally run it and was shocked at how small the opening was. I don't have a float switch on mine but I can definitely hear a difference when the siphon isn't flowing at 100%, the open pipe can make some noise. I've never had an issue with it as the open pipe should be able to handle the flow. Maybe try raising the float switch a little bit.
sleepydoc
03/03/2013, 01:12 PM
So this is exactly why the Herbie and Bean setups were invented. Full siphons are inherently unstable. It takes a relatively small amount of sludge (or a snail, or a fish, or...) to restrict the flow enough to cause an overflow, hence the need for a backup.
Of note, a herbie technically shouldn't have ANY water flowing down the backup; it should be tuned such that the water level is above the siphon and below the emergency backup. The reason being water flow down the backup can lead to buildup that is unrecognized so the capacity of your emergency drain ends up being less than you think and potentially inadequate. Yes, Very unlikely, but the whole point of these systems is to make a flood a 'never' event, not an 'unlikely' event.
jeremyjoslin
03/03/2013, 01:30 PM
Mine does the same thing from time to time. I've had a clump of bubble algae as well as small snails get through the strainer and even a tiny snail in the gate valve can be enough to raise the water level a little bit. I recently had to remove the piping under the tank to remove my sump and I looked in the gate valve at the position I normally run it and was shocked at how small the opening was. I don't have a float switch on mine but I can definitely hear a difference when the siphon isn't flowing at 100%, the open pipe can make some noise. I've never had an issue with it as the open pipe should be able to handle the flow. Maybe try raising the float switch a little bit.
Yes, I'll need to adjust the float switch a little up as the e-drain still had a little more capacity it could take.
Jus worried about being on vacation next time this happens.
jeremyjoslin
03/03/2013, 01:32 PM
some sludge will build on the gate acting like an adjustment so to speak
Hmmm. Sludge would accumulate slowly and drift the level up... this went from normal ops to failure in a matter of a few hours while I was at work.
jeremyjoslin
03/03/2013, 01:41 PM
So this is exactly why the Herbie and Bean setups were invented. Full siphons are inherently unstable. It takes a relatively small amount of sludge (or a snail, or a fish, or...) to restrict the flow enough to cause an overflow, hence the need for a backup.
Of note, a herbie technically shouldn't have ANY water flowing down the backup; it should be tuned such that the water level is above the siphon and below the emergency backup. The reason being water flow down the backup can lead to buildup that is unrecognized so the capacity of your emergency drain ends up being less than you think and potentially inadequate. Yes, Very unlikely, but the whole point of these systems is to make a flood a 'never' event, not an 'unlikely' event.
My e-drain didn't really fail... it just went from backup to primary leaving me with my float as last backup... which I see was triggered before the e-drain hit capacity.
I'm still at a loss on the main siphon though. It's not like it just had a little decrease in flow... it was as if it got clogged entirely. Even with the cycling of flow/no flow that the Apex created, didn't flush it- which I would have expected it to do.
Perhaps I just need to flush it wide open every few weeks?
I know the term Herbie has been bastardized, and that's why I've described my setup. I don't agree with the idea that a trickle will "ruin" the effectiveness of the e-drain, and I wouldn't trust my system to a "pure" Herbie as you describe. I need the double backup to be comfortable. I'm not here to debate which methods are better, only to describe my setup (and why) and ask for feedback on my case. All opinions, in that regard, are entirely welcome.
joedc
03/03/2013, 01:57 PM
Bottom line is if you tune your valve to 457, gph for example a few gph increase could be huge also I don't recomend a sponge on the intake just cover the box or use gutter guard considering a dirty sponge creates a second variable
jeremyjoslin
03/03/2013, 02:06 PM
Bottom line is if you tune your valve to 457, gph for example a few gph increase could be huge also I don't recomend a sponge on the intake just cover the box or use gutter guard considering a dirty sponge creates a second variable
Sorry if I was confusing. No sponge anywhere. I use egg crate zip-tied to make a 3d strainer so that a flat sheet of nori would never be able to clog it.
joedc
03/03/2013, 02:11 PM
Bit your saying the herbie failed all together and no clog was found at all?? Maybe your drop creates an acceleration problem then goes sucks air LOL weird but I did need to tune mine once it slimmed up
jeremyjoslin
03/03/2013, 02:18 PM
Bit your saying the herbie failed all together and no clog was found at all?? Maybe your drop creates an acceleration problem then goes sucks air LOL weird but I did need to tune mine once it slimmed up
Failed in the sense that the primary backup was close to being overwhelmed and my double backup had to cut the pump.
No spillage, and the system worked. But if I had been on vacay, I could not have flushed it.
It is a straight shot down 10 feet of 1.5" PVC, but no clog found. Working fine today. perfectly again.
Hopefully next time this happens I'll be home and be able to do a better post-mortem vs this last time where I called my sleeping wife and used FaceTime to show her which gate valve to open all the way.
Thanks everyone for all the ideas!
mr.maroonsalty
03/03/2013, 02:48 PM
I like your emergency back up. When your pump restarts does it run until the high water float trips it again? I'm a bit surprised that wasn't enough to flush the drain free. It seems to me it would have needed to be an almost complete clog for the second drain to get behind even as little as it did. I have seen people say that flushes are part of their regular maintenance routine.
jeremyjoslin
03/03/2013, 02:50 PM
I like your emergency back up. When your pump restarts does it run until the high water float trips it again? I'm a bit surprised that wasn't enough to flush the drain free. It seems to me it would have needed to be an almost complete clog for the second drain to get behind even as little as it did. I have seen people say that flushes are part of their regular maintenance routine.
Correct. Once the float switch gets triggered, it cuts the return pump and counts down 60 seconds. Then turns back on. Either the clog clears, or the water level trips the switch again.
This helps flush the drain, and gets warm/oxygenated water up to the display- even if it's only 5-10 gallons at a time. It could potentially cycle like this for days (until the pump burns out).
gmac_reef
03/04/2013, 12:31 AM
Sorry if I was confusing. No sponge anywhere. I use egg crate zip-tied to make a 3d strainer so that a flat sheet of nori would never be able to clog it.
I wonder if having a more restrictive strainer would prevent the problem? The valve on these setups tends to be adjusted to have a very small opening while the siphon is running... Would the 1/2" openings of the egg crate potentially be letting in a piece of algae or debris that would otherwise be caught by a strainer with smaller openings?
Whatever caused a temporary clog could have disintegrated by the time you inspected the system.
Just a guess, I think that is a pretty clever idea with the 60 sec timer btw.
uncleof6
03/04/2013, 03:00 AM
I know the term Herbie has been bastardized, and that's why I've described my setup. I don't agree with the idea that a trickle will "ruin" the effectiveness of the e-drain, and I wouldn't trust my system to a "pure" Herbie as you describe. I need the double backup to be comfortable. I'm not here to debate which methods are better, only to describe my setup (and why) and ask for feedback on my case. All opinions, in that regard, are entirely welcome.
A pipe with water flowing through it is not a back up of any kind. A "pure herbie" is far safer than the so called "hybrid" Herbie/Bean system, with a trickle running through the DRY emergency drain ..... Bean's system is safer than both of them.
A herbie, set up properly, is safer than using a float level switch, to save you from a flood--as you can see it did not--not really. If you want the double back up, you run a Bean system. The issue is you need a passive failsafe. If the fail safe is not passive, you don't have a "fail safe." A float switch, is an active device, and a pipe with water running through it is an active device.
The idea behind passive fail safety features, is that A) It can't fail, such as sufficient spare room in your sump for ALL power out drain down, or B) A failure of the "fail safe" makes the system safer, such as Bean's third pipe: the open channel.
The open channel on Bean's system, and a dry emergency with a trickle of flow through it, as you seem to prefer, are light years apart, with no relationship whatsoever.
It is not about which is better, it is about safe implementation--of either system--to prevent a flood. This is where the topic leaves the realm of opinion, and good information begins........debating opinions is like using sand paper for a washcloth, I quite agree. :)
barjam
03/04/2013, 09:26 AM
A pipe with water flowing through it is not a back up of any kind. A "pure herbie" is far safer than the so called "hybrid" Herbie/Bean system, with a trickle running through the DRY emergency drain ..... Bean's system is safer than both of them.
A herbie, set up properly, is safer than using a float level switch, to save you from a flood--as you can see it did not--not really. If you want the double back up, you run a Bean system. The issue is you need a passive failsafe. If the fail safe is not passive, you don't have a "fail safe." A float switch, is an active device, and a pipe with water running through it is an active device.
The idea behind passive fail safety features, is that A) It can't fail, such as sufficient spare room in your sump for ALL power out drain down, or B) A failure of the "fail safe" makes the system safer, such as Bean's third pipe: the open channel.
The open channel on Bean's system, and a dry emergency with a trickle of flow through it, as you seem to prefer, are light years apart, with no relationship whatsoever.
It is not about which is better, it is about safe implementation--of either system--to prevent a flood. This is where the topic leaves the realm of opinion, and good information begins........debating opinions is like using sand paper for a washcloth, I quite agree. :)
On a herbie if your secondary is largely oversized compared to the the flow of the return and there is a trickle that is acceptable too. If they are closely matched I agree with you.
jeremyjoslin
03/04/2013, 09:27 AM
I wonder if having a more restrictive strainer would prevent the problem? The valve on these setups tends to be adjusted to have a very small opening while the siphon is running... Would the 1/2" openings of the egg crate potentially be letting in a piece of algae or debris that would otherwise be caught by a strainer with smaller openings?
Whatever caused a temporary clog could have disintegrated by the time you inspected the system.
Just a guess, I think that is a pretty clever idea with the 60 sec timer btw.
I like this idea and the math seems right.
jeremyjoslin
03/04/2013, 09:33 AM
A pipe with water flowing through it is not a back up of any kind. A "pure herbie" is far safer than the so called "hybrid" Herbie/Bean system, with a trickle running through the DRY emergency drain ..... Bean's system is safer than both of them.
A herbie, set up properly, is safer than using a float level switch, to save you from a flood--as you can see it did not--not really. If you want the double back up, you run a Bean system. The issue is you need a passive failsafe. If the fail safe is not passive, you don't have a "fail safe." A float switch, is an active device, and a pipe with water running through it is an active device.
The idea behind passive fail safety features, is that A) It can't fail, such as sufficient spare room in your sump for ALL power out drain down, or B) A failure of the "fail safe" makes the system safer, such as Bean's third pipe: the open channel.
The open channel on Bean's system, and a dry emergency with a trickle of flow through it, as you seem to prefer, are light years apart, with no relationship whatsoever.
It is not about which is better, it is about safe implementation--of either system--to prevent a flood. This is where the topic leaves the realm of opinion, and good information begins........debating opinions is like using sand paper for a washcloth, I quite agree. :)
I would say that my second pipe (e-drain) is a passive fail safe. Consider that both primary (full siphon) and e-drain (trickle) are both 1.5" pipes with a straight shot down into the basement (no turns but maybe a 15 degree bend). The siphon is chocked down by ??% but is significant. The e-drain is wide open. By math, the e-drain will always be able to handle the entire load because the choked % is much greater than the the small volume taken up by the trickle.
The only thing that failed was my full testing... my float switch is too low compared with the height of the drain, and so I've taken the height of my e-drain down just a little.
mr.maroonsalty
03/04/2013, 01:13 PM
It is not about which is better, it is about safe implementation--of either system--to prevent a flood. This is where the topic leaves the realm of opinion, and good information begins........debating opinions is like using sand paper for a washcloth, I quite agree. :)
I think it is very kool that you got an email telling you your syphon backed up! As one whose not afraid of getting dirty to the point of needing a pumas stone to help clean myself, that you have a fail safe that takes flood control entirely out of the unknown hands of God is commendable! It must be much more comfortable being away knowing that you will be noticified you're having a drain problem than not knowing if you are relying on a system that has already failed once.
barjam
03/04/2013, 04:35 PM
What sort of valve are you using? I use the nicer valves from Home Depot/Lowes with the unions on either end. These are far easier to adjust then the cheap ones. I hear gate valves are better still.
In the tanks I have setup herbie drains have been set and forget. I don't remember the last time I adjusted it.
jeremyjoslin
03/04/2013, 08:04 PM
What sort of valve are you using? I use the nicer valves from Home Depot/Lowes with the unions on either end. These are far easier to adjust then the cheap ones. I hear gate valves are better still.
In the tanks I have setup herbie drains have been set and forget. I don't remember the last time I adjusted it.
I use a gate valve. 1.5"
sleepydoc
03/04/2013, 08:28 PM
I wonder if having a more restrictive strainer would prevent the problem?
A more restrictive strainer is a double-edged sword. Any strainer, by definition, will catch debris. Whether the restriction is at the valve, in the middle of the pipe, or at the strainer at the opening makes no difference, the water flow will decrease and start to flow down the backup.
The valve on these setups tends to be adjusted to have a very small opening while the siphon is running.
Which means they are more prone and more susceptible to blockages from debris. The way most gate valves work, there ends up being a crescent-shaped opening meaning there is a lot of edge area to catch stuff and give resistance to flow, which goes back to the point I made earlier about full siphons being unstable. It also means that the capacity of the emergency is significantly higher than it needs to be, since the full siphon is running lower than it's potential capacity.
I would say that my second pipe (e-drain) is a passive fail safe....The e-drain is wide open. By math, the e-drain will always be able to handle the entire load because the choked % is much greater than the the small volume taken up by the trickle.
The only thing that failed was my full testing... my float switch is too low compared with the height of the drain, and so I've taken the height of my e-drain down just a little.
As I mentioned earlier, if there is water flowing in the emergency drain, there is the potential for 'crud' to build up in it as well, so the true capacity is not actually known, which is Uncle's point. When he speaks of passive vs active protection, passive means that the system itself provides the protection without any intervention. The system you have set up. requires active intervention by the controller to shut off the pump.
Now I readily admit that the likelihood of both the e-drain clogging to the point that it can't handle the flow and the controller making a mistake or float switch failing is quite small, but it's important to realize the difference and the fact that you are substituting something that is an absolute (the flow capacity of a previously dry pipe) with something else that is probable, but unknown.
Since you already have a controller and a float switch, why don't you either add another switch or move the existing one to a point below where the emergency drain begins to overflow to give you an alert to adjust your gate valve. That would give you the best of both worlds.
mr.maroonsalty
03/04/2013, 11:01 PM
Would you rather run a single emergency drain alone for a week or have a kill switch in place as well? facts and opinions aside, keep the drain dry or give it a little trickle, it seems an easy answer to me. Staying safely within the drains limitations has always been design rule, now that many are pushing that limit with syphons thorough testing of blockage situations is a must. I think its perfect that you can be told of a syphon problem; I could see adding a second sensor: one to tell you the syphon is falling behind and then the kill switch, and I'm a gear and pin timer type.
jeremyjoslin
03/05/2013, 10:17 AM
As an update, I lowered the height of the e-drain 48 hours ago and adjusted the gate valve to the most minor trickle I could tune it to.
Everything else I left the same until I decide how I'm going to tackle this more permanently.
When I woke up this morning, the tank was cycling again with the kill switch. ***?
I turned off the pump, and let it sit for awhile. Just turned it back on and everything is working fine again. No clogs dislodged or anything.
I'm starting to think this may be a PUMP issue that is overwhelming my drains. Electricity spike? Maybe its running bad all of the time, and then hiccups into working correctly thus increasing flow considerably?
After all, it is a hammerhead running without choke, with a manifold to a few small tanks downstairs and skimmer. There's about 13 feet of head.
I'll need some calculators and references, but I guess I need to re-check how many GPH a 1.5" drain can take at siphon and compare that to what a HH can push at 13 feet.
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