Silent and Failsafe Overflow System - Page 368

uncleof6 · 09/11/2016, 06:45 PM

You get what you pay for in a valve. Sure, you will pay a couple bucks for the name, but there is a rather significant quality difference betwen a Spears valve, and a "budget" valve. I don't know the branding of the "budget" gate valves sell, however, They do appear to be KBI. (Matching patent numbers.) KBI is U.S. made, so the quality will be higher than imported budget valves.

The most obivious difference, other than "quality" (very subject) is in the ease of disassembly. They both disassemble, it is just a lot easier to get a Spears apart in place, than the KBI is. The KBI is more prone to stem leaks than the Spears. However, both the stem seal, and the "gate" are replaceable items. ETSS used the KBI sch40 gates with their high end equiment, and KBI is probably the most common gate in the hobby (at some point WalMart was selling them.) If wanting to service it in place I would strongly recommend you spend the bucks the first time around.

Another thing I noticed is you are planning on running two DC pumps full open, for a 375 gallon tank. The whole point of running a DC pump, is the energy savings, but still have good flow at a reasonable head loss. However, running two pumps is always (I am sure an exception can be found, but that is not the point) less efficient than running a single larger pump that will do the job on its own.

In your case you are planning on running 2 DC12000 pumps, to service a 375 gallon tank. These are good pumps, when used where it is "appropriate," however the two together will eat up 278 watts, (I believe it is closer to 150watts per pump due to AC/DC conversion, but 278 makes the point.) Depending on how much you do or do not engineer your plumbing, you will probably get ~ 3200gph plus or minus total with both pumps running. (from flow curves, using around 6' - 7' total head, the mid-point on the flow curve: the point where the losses have eaten up half your theoretical max.)

A Barracuda will pump 3843gph @ 4' (236watts) and 3333 @ 8' (248watts,) and will also be more "reliable," because there are no electronics involved. Clear winner for everything that counts: Barracuda.

When even the RLC calculator says you need a minimum of 45" of overflow for 3000gph, 24" (60% of 40") comes up way short... Because you don't have a good amount of overflow, and are channeling the flow (both with 4 seperate slots, and each slot further channeled with "grates" you are most likely not going to enjoy the noise, which is part of the reason one would use a silent drain system, I would think.

I built a 300gallon + tank around 6 years ago, with an internal external setup, full length internal full length external. Never had the external box dump the entire volume into the sump (the plumbing does not allow it.) If I stop and think about it, it was pretty much a waste of time as the standard BA setup would have been just fine, and there was no real benefit.

Acrylic tanks present more of a problem due to the euro-brace, however I do think that you will be better off installing an internal weir and using through holes as a pass through to the plumbing.

jason2459 · 09/11/2016, 08:14 PM

I've always used a cheap ball valve. I'd suggest a spears gate valve for ease of tuning. On a ball valve the tiniest nudge does a lot. Though once dialed in I never did touch it again.

Post #9135 shows my current ball valve conglomeration.
http://www.reefcentral.com/forums/sh...php?p=24699103

pfoxgrover · 09/12/2016, 08:14 AM

Quote:

Originally Posted by uncleof6

You get what you pay for in a valve. Sure, you will pay a couple bucks for the name, but there is a rather significant quality difference between a Spears valve, and a "budget" valve. I don't know the branding of the "budget" gate valves sell, however, They do appear to be KBI. (Matching patent numbers.) KBI is U.S. made, so the quality will be higher than imported budget valves.

The most obvious difference, other than "quality" (very subject) is in the ease of disassembly. They both disassemble; it is just a lot easier to get a Spears apart in place, than the KBI is. The KBI is more prone to stem leaks than the Spears. However, both the stem seal, and the "gate" are replaceable items. ETSS used the KBI sch40 gates with their high end equipment, and KBI is probably the most common gate in the hobby (at some point WalMart was selling them.) If wanting to service it in place I would strongly recommend you spend the bucks the first time around.

Good information.Thanks.

Quote:

Originally Posted by uncleof6

Another thing I noticed is you are planning on running two DC pumps full open, for a 375 gallon tank. The whole point of running a DC pump, is the energy savings, but still have good flow at a reasonable head loss. However, running two pumps is always (I am sure an exception can be found, but that is not the point) less efficient than running a single larger pump that will do the job on its own.

In your case you are planning on running 2 DC12000 pumps, to service a 375 gallon tank. These are good pumps, when used where it is "appropriate," however the two together will eat up 278 watts, (I believe it is closer to 150watts per pump due to AC/DC conversion, but 278 makes the point.) Depending on how much you do or do not engineer your plumbing, you will probably get ~ 3200gph plus or minus total with both pumps running. (from flow curves, using around 6' - 7' total head, the mid-point on the flow curve: the point where the losses have eaten up half your theoretical max.)

A Barracuda will pump 3843gph @ 4' (236watts) and 3333 @ 8' (248watts,) and will also be more "reliable," because there are no electronics involved. Clear winner for everything that counts: Barracuda.

I am currently running the two DCT12000 pumps on my 240g both at a low setting. I had a DC12000 fail when I was on vacation and luckily I got my friend to come over and fix it when the tank sitter noticed it. After that I separated the plumbing and installed the second pump. The system will operate with either pump failed and I feel much safer with the redundancy. Eventually I would like to get them on separate circuits as well. Also I prefer submersible pumps. I can see your point about the efficiency of one pump though.

Quote:

Originally Posted by uncleof6

When even the RLC calculator says you need a minimum of 45" of overflow for 3000gph, 24" (60% of 40") comes up way short... Because you don't have a good amount of overflow, and are channeling the flow (both with 4 separate slots, and each slot further channeled with "grates" you are most likely not going to enjoy the noise, which is part of the reason one would use a silent drain system, I would think.
I built a 300gallon + tank around 6 years ago, with an internal external setup, full length internal full length external. Never had the external box dump the entire volume into the sump (the plumbing does not allow it.) If I stop and think about it, it was pretty much a waste of time as the standard BA setup would have been just fine, and there was no real benefit.
Acrylic tanks present more of a problem due to the euro-brace, however I do think that you will be better off installing an internal weir and using through holes as a pass through to the plumbing.

I will consider adding a small grate covered removable weir to the inside of the tank and keep the plumbing in the overflow box. I imagine I could make something not much bigger than the grate I pictured in the earlier post and perhaps as thin as 1/2 inch or so.

Thanks,
Paul

pfoxgrover · 09/12/2016, 08:19 AM

Quote:

Originally Posted by jason2459

I've always used a cheap ball valve. I'd suggest a spears gate valve for ease of tuning. On a ball valve the tiniest nudge does a lot. Though once dialed in I never did touch it again.

Post #9135 shows my current ball valve conglomeration.
http://www.reefcentral.com/forums/sh...php?p=24699103

Good to know. Thanks

uncleof6 · 09/12/2016, 03:41 PM

Redundancy: a part in a machine, system, etc., that has the same function as another part and that exists so that the entire machine, system, etc., will not fail if the main part fails. E.G. the probability of the "redundant" part failing is at or near zero under normal conditions, and the probability only increases if the "main" part fails. In other words the "redundant part" is not in use.

In a system with both identical pumps running, the failure probability of the pumps is equal. That is not redundancy, as both pumps together are the "main part."

A second backup, or second failsafe is a redundant failsafe, used only if the primary backup/failsafe fails.

These pumps have a "rep" for failing, though it is not so widespread as claims state. Just the same, with both running it is just as likely that both will fail at the same time, as it is that only one will fail. You would need a third pump not running, to actually get to where you feel you are. The third pump would be the actual primary failsafe, not a redundant failsafe.

This is the same thing as the misconceptions concerning the wet secondary used in a Herbie, and why it is not really safe.

On the overflow: I don't know what you define as "small." I do know how some others define it, so this is generalized. The concepts discussed are very significant to the functionality of a system. The concepts directly affect the gas exchange and organic removal, via surface renewal. This directly affects the performance of the skimmer, and any other method where concentrations of organics in the water drives the removal rates. "Small" usually tends to indicate a left hand turn from a path that is known to be "best" for the system, based on how this stuff actually works.
Just sayin...

pfoxgrover · 09/12/2016, 06:28 PM

The probability of failure for me has been high. Some failures were electrical and some mechanical.
The probability of them both failing on the same day or week or while I'm on vacation is significantly reduced.
I have already had it save me from a prolonged outage in the year I've been running both of them at the same time.

What I mean by small is the height and thickness of the internal part of the overflow. I was not referring to the length.

sleepydoc · 09/12/2016, 09:11 PM

Quote:

Originally Posted by uncleof6

Redundancy: a part in a machine, system, etc., that has the same function as another part and that exists so that the entire machine, system, etc., will not fail if the main part fails. E.G. the probability of the "redundant" part failing is at or near zero under normal conditions, and the probability only increases if the "main" part fails. In other words the "redundant part" is not in use.

In a system with both identical pumps running, the failure probability of the pumps is equal. That is not redundancy, as both pumps together are the "main part."

A second backup, or second failsafe is a redundant failsafe, used only if the primary backup/failsafe fails.

These pumps have a "rep" for failing, though it is not so widespread as claims state. Just the same, with both running it is just as likely that both will fail at the same time, as it is that only one will fail. You would need a third pump not running, to actually get to where you feel you are. The third pump would be the actual primary failsafe, not a redundant failsafe.

I would consider it 'partially redundant,' in the same way using 2 smaller heaters instead of one big one. The system may not be fully functional at the same level of flow as it would with both, but it would still have some flow, even if at a reduced level, which beats no flow at all.

LXXero · 09/12/2016, 09:56 PM

in the computer world we would call it "hot/hot" or "active/active" redundancy as opposed to "master/slave" or "active/failover" redundancy.

both methods are valid approaches, however sometimes "staggering" components is smart with active/active, if you buy all the parts at once, they have a higher chance to all fail around the same time. in practice this is rarely done and usually any failures would be spaced out enough not to matter.

sleepydoc · 09/13/2016, 08:07 AM

Staggering would make sense if it there were issues with a particular batch of devices since you could theoretically get devices from different batches and avoid having problems with all of them. If the failure is intrinsic to the device, though, the only way it would matter is if the MTBF is accurate to a time frame less than that needed to fix the broken device before the backup/secondary failed (meaning pump 2 would fail before pump 1 could be replaced in this case,) but we digress from the thread...

Relating redundancy to the Bean system, the reason it is so reliable is because it has that redundancy. With a return pump, partial redundancy is acceptable since the system should still survive without any catastrophes at half flow should one pump fail. With an overflow system that's not necessarily the case.

Take the 'wet Herbie' as an example - full siphon on one pipe with a trickle on the second and no dry emergency like the bean has. By design, the siphon cannot handle the full flow of the return pump and will flood if the trickle pipe gets blocked. In other words it has a single potential failure point. Many people argue that this is unlikely to happen and/or take precautions to make it less likely to happen, and are comfortable with the risks, which is fine. Safety is about reducing risks to an acceptable level and balancing the risks, the costs of mitigating the risks and the costs of a failure (i.e. will the flood be in your living room, or in an unfinished basement?) Ultimately you should understand the risks, though.

The Bean takes the Herbie system one or 2 steps further by adding redundancy - both the dry emergency is always ready if needed, and the airline tubing for the open channel can convert it to a full siphon, increasing it's capacity. In this case, both these systems provide full redundancy - the open channel and the dry emergency can potentially handle the entire flow of the system without a flood. I believe that both Uncle and Bean have had cases where both the siphon and the open channel have gotten clogged, meaning they were saved by the dry emergency, so although it may be an uncommon occurrence, it can happen.

jason2459 · 09/13/2016, 12:39 PM

Its always good to test as many scenarios as you can. Its better to happen while you have some control then when you just left out of town for several days to weeks.

I test by closing up the siphon. Then test closing up just the open. Turning of and back on the return pump.

Then close the siphon and the open. Again turning off and on the return pump.

See what happens.

nanomania · 09/13/2016, 09:50 PM

Question For backsump overflow:
Tank 54 x24 x24"
Sump is 6.5" width at the back.
Return Pump eheim compact 2000

Howlong should the overflow surface skimmer should be? How big should the teeth be?

Sent from my GT-N7100 using Tapatalk

LXXero · 09/14/2016, 12:22 AM

Quote:

Originally Posted by nanomania

Question For backsump overflow:
Tank 54 x24 x24"
Sump is 6.5" width at the back.
Return Pump eheim compact 2000

Howlong should the overflow surface skimmer should be? How big should the teeth be?

haha that's almost become a loaded question around here.

my 120g tank is 48x24x24 and i went with 18" long. it's arbitrary at some point though. The best is "as big as you can go" meaning full-length, coast to coast style, or something even more ridiculous like multi-edge overflow, but no one reall ydoes that. I'm sure anything 16 - 24" would be fine in reality, just wouldn't be "quite" as good as full-length.

nanomania · 09/14/2016, 12:24 AM

Quote:

Originally Posted by LXXero

haha that's almost become a loaded question around here.

my 120g tank is 48x24x24 and i went with 18" long. it's arbitrary at some point though. The best is "as big as you can go" meaning full-length, coast to coast style, or something even more ridiculous like multi-edge overflow, but no one reall ydoes that. I'm sure anything 16 - 24" would be fine in reality, just wouldn't be "quite" as good as full-length.

Well mine is backsump, not sump at bottom. So no pipes etc. Can i go 12" wud it be enough??

Sent from my GT-N7100 using Tapatalk

LXXero · 09/14/2016, 02:04 AM

Quote:

Originally Posted by nanomania

Well mine is backsump, not sump at bottom. So no pipes etc. Can i go 12" wud it be enough??

Sent from my GT-N7100 using Tapatalk

it would probably handle the flow, assuming you keep it reasonable. However, the skimming effectiveness will be reduced at that size. You might want to go toothless if possible, to maximum use of the space.

nanomania · 09/14/2016, 02:07 AM

Quote:

Originally Posted by LXXero

it would probably handle the flow, assuming you keep it reasonable. However, the skimming effectiveness will be reduced at that size. You might want to go toothless if possible, to maximum use of the space.

That can cause fishes and inverts going into the sump

This is what i have. 30cm. Ordered from fish street

Sent from my GT-N7100 using Tapatalk

Outdrsyguy1 · 09/14/2016, 12:43 PM

tried to find this answer as I saw it once before, but couldn't find again.

What sets the height of the water in your overflow? Is it the height of the "trickle" pipe?

Having issues where my overflow water level is too high and basically raises the tank water level rather than flowing through the weir. I'm guessing it's recommended to have the overflow level lower than the tank by 1/4", 1/2"?

LXXero · 09/14/2016, 12:48 PM

Quote:

Originally Posted by Outdrsyguy1

tried to find this answer as I saw it once before, but couldn't find again.

What sets the height of the water in your overflow? Is it the height of the "trickle" pipe?

Having issues where my overflow water level is too high and basically raises the tank water level rather than flowing through the weir. I'm guessing it's recommended to have the overflow level lower than the tank by 1/4", 1/2"?

open your siphon's valve more?

technically you should be setting that water level with your siphon valve. opening and closing the valve on your full siphon will be what sets the water level in there. The trickle pipe will ultimately set the high point though.

too high is when it floods on your floor, imho. I don't think it matters whether the water level is higher or lower, as long as it's got margin that it's not close to spilling out, that's all that i care about.

Outdrsyguy1 · 09/14/2016, 01:19 PM

Normally it sits like this.

Crack it a hair open, and I mean just a tiny tiny hair on a decent cepex calve and after about 5*+ minutes it eventually get to here and starts gurgling. I'm thinking my trickle tube on the left is too high?

Floyd R Turbo · 09/14/2016, 01:34 PM

Both your OC and siphon are way too high IMO

Siphon can be all the way at the bottom of your box. Literally, just enough pipe (black, in your case) to insert into the bulkhead and then into the first 90 and that's it.

OC can be just a hair above it or even at the same level. But I don't see an airline on your OC?? That is what keeps it from siphoning. You run the airline up to just below the emergency and that kicks the OC over to siphon when the level gets close to the emergency pipe

Outdrsyguy1 · 09/14/2016, 02:11 PM

gotcha, thanks Floyd!
I had them higher because I didn't want my whole overflow to drain down on a power shutdown (it's a 10' long overflow so it holds a decent amount of water).
I'll get that anti-siphon tube done this weekend, just need to hit up bean's website for the parts.

Floyd R Turbo · 09/14/2016, 02:14 PM

not sure what you mean, i.e. why you are worrying about draining the overflow box?

BTW you have a seam separating in those pics. Vertical seam to the left of the OC.

Outdrsyguy1 · 09/14/2016, 03:20 PM

yes, i didn't want to drain the entire overflow on shutdown.

What do you mean by vertical seam? an issue with my tank or how the pics appeared on the page?

LXXero · 09/14/2016, 07:11 PM

Quote:

Originally Posted by Outdrsyguy1

yes, i didn't want to drain the entire overflow on shutdown.

What do you mean by vertical seam? an issue with my tank or how the pics appeared on the page?

i agree it's not worth draining that whole chamber on shut down, at least not on an internal overflow. on an external that's not as big of a deal.

again, i'd ditch the double-90s entirely on the siphon line. All you need is a strainer, and it can be 6" from the top, so it wont drain the whole overflow, just 6" worth.

Is there an airhole drilled into your open channel? It's hard to tell from the pics.

I think he's referring to that seam to the left of your open channel, whatever that acrylic thing there is.

sleepydoc · 09/14/2016, 09:40 PM

The steady state level in the overflow is determined by 2 things: The level of the open channel and to a lesser extent the valve on the siphon.

Consider how the Bean is designed to operate - the siphon takes the majority of the flow with the open channel taking the flow above what the siphon can't handle.

Imagine that the siphon is established and the siphon flow and the return pump flow were perfectly matched, the water level could be anywhere between the inlet to the siphon and the ledge of the open channel (the point at the top of the inverted U where the water just makes it over the top to go down the standpipe.)

Now consider that the flow is slightly greater than the siphon can handle. The water level will rise until it starts making it over the ledge of the open channel. The more flow the open channel needs to handle, the higher the water will rise. This will continue until the flow in the open channel is 'maxed out,' at which point the water level rises to the level of the dry emergency.

For an external overflow like you describe, you don't necessarily need the inverted U, but if you omit it, the opening to the siphon pipe needs to be far enough below the surface that it doesn't entrain air. As Outdrsyguy1 noted, the further down in the box the siphon opening is, the more water will drain out when the power is cut. As long as your sump can handle the volume this isn't an issue; it should start back up again either way, but if you are interested in minimizing the amount that drains down, the inverted U will allow the opening to the siphon channel to be placed higher in the box than a straight open pipe.

I agree with Floyd - the pipes are too high in the box

Outdrsyguy1 · 09/14/2016, 11:09 PM

thanks a ton everyone, i need to tweak it and see how things go. I'll drill the siphon line hole and install the fittings and move things down a bit.

09/11/2016, 06:45 PM	#9176
uncleof6 Registered Member Join Date: Jul 2004 Location: AWOL Posts: 12,013	You get what you pay for in a valve. Sure, you will pay a couple bucks for the name, but there is a rather significant quality difference betwen a Spears valve, and a "budget" valve. I don't know the branding of the "budget" gate valves sell, however, They do appear to be KBI. (Matching patent numbers.) KBI is U.S. made, so the quality will be higher than imported budget valves. The most obivious difference, other than "quality" (very subject) is in the ease of disassembly. They both disassemble, it is just a lot easier to get a Spears apart in place, than the KBI is. The KBI is more prone to stem leaks than the Spears. However, both the stem seal, and the "gate" are replaceable items. ETSS used the KBI sch40 gates with their high end equiment, and KBI is probably the most common gate in the hobby (at some point WalMart was selling them.) If wanting to service it in place I would strongly recommend you spend the bucks the first time around. Another thing I noticed is you are planning on running two DC pumps full open, for a 375 gallon tank. The whole point of running a DC pump, is the energy savings, but still have good flow at a reasonable head loss. However, running two pumps is always (I am sure an exception can be found, but that is not the point) less efficient than running a single larger pump that will do the job on its own. In your case you are planning on running 2 DC12000 pumps, to service a 375 gallon tank. These are good pumps, when used where it is "appropriate," however the two together will eat up 278 watts, (I believe it is closer to 150watts per pump due to AC/DC conversion, but 278 makes the point.) Depending on how much you do or do not engineer your plumbing, you will probably get ~ 3200gph plus or minus total with both pumps running. (from flow curves, using around 6' - 7' total head, the mid-point on the flow curve: the point where the losses have eaten up half your theoretical max.) A Barracuda will pump 3843gph @ 4' (236watts) and 3333 @ 8' (248watts,) and will also be more "reliable," because there are no electronics involved. Clear winner for everything that counts: Barracuda. When even the RLC calculator says you need a minimum of 45" of overflow for 3000gph, 24" (60% of 40") comes up way short... Because you don't have a good amount of overflow, and are channeling the flow (both with 4 seperate slots, and each slot further channeled with "grates" you are most likely not going to enjoy the noise, which is part of the reason one would use a silent drain system, I would think. I built a 300gallon + tank around 6 years ago, with an internal external setup, full length internal full length external. Never had the external box dump the entire volume into the sump (the plumbing does not allow it.) If I stop and think about it, it was pretty much a waste of time as the standard BA setup would have been just fine, and there was no real benefit. Acrylic tanks present more of a problem due to the euro-brace, however I do think that you will be better off installing an internal weir and using through holes as a pass through to the plumbing. __________________ "Things should be made as simple as possible, but not simpler." (oft attributed to Einstein; most likely paraphrasing by Roger Sessions; compactly articulates the principle of Occam's Razor) Current Tank Info: 325 6' wide Reef Last edited by uncleof6; 09/11/2016 at 07:09 PM.

09/11/2016, 08:14 PM	#9177
jason2459 Registered Member Join Date: Jul 2009 Location: Iowa Posts: 9,671	I've always used a cheap ball valve. I'd suggest a spears gate valve for ease of tuning. On a ball valve the tiniest nudge does a lot. Though once dialed in I never did touch it again. Post #9135 shows my current ball valve conglomeration. http://www.reefcentral.com/forums/sh...php?p=24699103 __________________ rebuild and recovery log: No more red house, you'll have to click on my name and visit my homepage! You can check out my parameters at reeftronics dot net website and look for my username. Current Tank Info: 180g mixed reef w/ a beananimal overflow to a dolomite RRUGF. \| 20g long G. Smithii Mantis Tank

09/12/2016, 03:41 PM	#9180
uncleof6 Registered Member Join Date: Jul 2004 Location: AWOL Posts: 12,013	Redundancy: a part in a machine, system, etc., that has the same function as another part and that exists so that the entire machine, system, etc., will not fail if the main part fails. E.G. the probability of the "redundant" part failing is at or near zero under normal conditions, and the probability only increases if the "main" part fails. In other words the "redundant part" is not in use. In a system with both identical pumps running, the failure probability of the pumps is equal. That is not redundancy, as both pumps together are the "main part." A second backup, or second failsafe is a redundant failsafe, used only if the primary backup/failsafe fails. These pumps have a "rep" for failing, though it is not so widespread as claims state. Just the same, with both running it is just as likely that both will fail at the same time, as it is that only one will fail. You would need a third pump not running, to actually get to where you feel you are. The third pump would be the actual primary failsafe, not a redundant failsafe. This is the same thing as the misconceptions concerning the wet secondary used in a Herbie, and why it is not really safe. On the overflow: I don't know what you define as "small." I do know how some others define it, so this is generalized. The concepts discussed are very significant to the functionality of a system. The concepts directly affect the gas exchange and organic removal, via surface renewal. This directly affects the performance of the skimmer, and any other method where concentrations of organics in the water drives the removal rates. "Small" usually tends to indicate a left hand turn from a path that is known to be "best" for the system, based on how this stuff actually works. Just sayin... __________________ "Things should be made as simple as possible, but not simpler." (oft attributed to Einstein; most likely paraphrasing by Roger Sessions; compactly articulates the principle of Occam's Razor) Current Tank Info: 325 6' wide Reef

09/13/2016, 08:07 AM	#9184
sleepydoc Registered Member Join Date: Oct 2011 Location: Minneapolis, MN Posts: 3,907	Staggering would make sense if it there were issues with a particular batch of devices since you could theoretically get devices from different batches and avoid having problems with all of them. If the failure is intrinsic to the device, though, the only way it would matter is if the MTBF is accurate to a time frame less than that needed to fix the broken device before the backup/secondary failed (meaning pump 2 would fail before pump 1 could be replaced in this case,) but we digress from the thread... Relating redundancy to the Bean system, the reason it is so reliable is because it has that redundancy. With a return pump, partial redundancy is acceptable since the system should still survive without any catastrophes at half flow should one pump fail. With an overflow system that's not necessarily the case. Take the 'wet Herbie' as an example - full siphon on one pipe with a trickle on the second and no dry emergency like the bean has. By design, the siphon cannot handle the full flow of the return pump and will flood if the trickle pipe gets blocked. In other words it has a single potential failure point. Many people argue that this is unlikely to happen and/or take precautions to make it less likely to happen, and are comfortable with the risks, which is fine. Safety is about reducing risks to an acceptable level and balancing the risks, the costs of mitigating the risks and the costs of a failure (i.e. will the flood be in your living room, or in an unfinished basement?) Ultimately you should understand the risks, though. The Bean takes the Herbie system one or 2 steps further by adding redundancy - both the dry emergency is always ready if needed, and the airline tubing for the open channel can convert it to a full siphon, increasing it's capacity. In this case, both these systems provide full redundancy - the open channel and the dry emergency can potentially handle the entire flow of the system without a flood. I believe that both Uncle and Bean have had cases where both the siphon and the open channel have gotten clogged, meaning they were saved by the dry emergency, so although it may be an uncommon occurrence, it can happen. __________________ ~~~~~~~~~~~~~~~~~~~~~ 120 gallon, coast to coast overflow w/beananimal overflow. Waveline DC 10000 II return pump, 40 gal sump, Octopus XS200 skimmer, T5 lighting

09/13/2016, 12:39 PM	#9185
jason2459 Registered Member Join Date: Jul 2009 Location: Iowa Posts: 9,671	Its always good to test as many scenarios as you can. Its better to happen while you have some control then when you just left out of town for several days to weeks. I test by closing up the siphon. Then test closing up just the open. Turning of and back on the return pump. Then close the siphon and the open. Again turning off and on the return pump. See what happens. __________________ rebuild and recovery log: No more red house, you'll have to click on my name and visit my homepage! You can check out my parameters at reeftronics dot net website and look for my username. Current Tank Info: 180g mixed reef w/ a beananimal overflow to a dolomite RRUGF. \| 20g long G. Smithii Mantis Tank

09/12/2016, 06:28 PM	#9181
pfoxgrover Registered Member Join Date: May 2012 Location: Southern California Posts: 313	The probability of failure for me has been high. Some failures were electrical and some mechanical. The probability of them both failing on the same day or week or while I'm on vacation is significantly reduced. I have already had it save me from a prolonged outage in the year I've been running both of them at the same time. What I mean by small is the height and thickness of the internal part of the overflow. I was not referring to the length.

09/12/2016, 09:56 PM	#9183
LXXero Moved On Join Date: May 2016 Location: Colorado Posts: 565	in the computer world we would call it "hot/hot" or "active/active" redundancy as opposed to "master/slave" or "active/failover" redundancy. both methods are valid approaches, however sometimes "staggering" components is smart with active/active, if you buy all the parts at once, they have a higher chance to all fail around the same time. in practice this is rarely done and usually any failures would be spaced out enough not to matter.

09/13/2016, 09:50 PM	#9186
nanomania Registered Member Join Date: Mar 2011 Location: mumbai, india Posts: 1,101	Question For backsump overflow: Tank 54 x24 x24" Sump is 6.5" width at the back. Return Pump eheim compact 2000 Howlong should the overflow surface skimmer should be? How big should the teeth be? Sent from my GT-N7100 using Tapatalk __________________ TRY BUYING CAPTIVE BRED ANIMALS/FISHES/INVERTS... DONT BUY A DOG, ADOPT THEM..... SAVE NATURE..... JUNGLES AND OCEANS RULE.....

09/14/2016, 12:43 PM	#9191
Outdrsyguy1 Registered Member Join Date: May 2013 Posts: 81	tried to find this answer as I saw it once before, but couldn't find again. What sets the height of the water in your overflow? Is it the height of the "trickle" pipe? Having issues where my overflow water level is too high and basically raises the tank water level rather than flowing through the weir. I'm guessing it's recommended to have the overflow level lower than the tank by 1/4", 1/2"?

09/14/2016, 01:19 PM	#9193
Outdrsyguy1 Registered Member Join Date: May 2013 Posts: 81	Normally it sits like this. Crack it a hair open, and I mean just a tiny tiny hair on a decent cepex calve and after about 5*+ minutes it eventually get to here and starts gurgling. I'm thinking my trickle tube on the left is too high?

09/14/2016, 01:34 PM	#9194
Floyd R Turbo Either busy or sleeping Join Date: Oct 2009 Location: West Des Moines, IA Posts: 4,265 Blog Entries: 15	Both your OC and siphon are way too high IMO Siphon can be all the way at the bottom of your box. Literally, just enough pipe (black, in your case) to insert into the bulkhead and then into the first 90 and that's it. OC can be just a hair above it or even at the same level. But I don't see an airline on your OC?? That is what keeps it from siphoning. You run the airline up to just below the emergency and that kicks the OC over to siphon when the level gets close to the emergency pipe __________________ Algae Scrubber Basics!!! GOOGLE "algaescrubber zoho" General Interest Forums --> Advanced Topics --> Algae Scrubber Basics (sticky) --> POSTS #3251-64 (Basics), #5206 (Cleaning), #6884 (LEDs), #729

09/14/2016, 02:11 PM	#9195
Outdrsyguy1 Registered Member Join Date: May 2013 Posts: 81	gotcha, thanks Floyd! I had them higher because I didn't want my whole overflow to drain down on a power shutdown (it's a 10' long overflow so it holds a decent amount of water). I'll get that anti-siphon tube done this weekend, just need to hit up bean's website for the parts.

09/14/2016, 02:14 PM	#9196
Floyd R Turbo Either busy or sleeping Join Date: Oct 2009 Location: West Des Moines, IA Posts: 4,265 Blog Entries: 15	not sure what you mean, i.e. why you are worrying about draining the overflow box? BTW you have a seam separating in those pics. Vertical seam to the left of the OC. __________________ Algae Scrubber Basics!!! GOOGLE "algaescrubber zoho" General Interest Forums --> Advanced Topics --> Algae Scrubber Basics (sticky) --> POSTS #3251-64 (Basics), #5206 (Cleaning), #6884 (LEDs), #729

09/14/2016, 03:20 PM	#9197
Outdrsyguy1 Registered Member Join Date: May 2013 Posts: 81	yes, i didn't want to drain the entire overflow on shutdown. What do you mean by vertical seam? an issue with my tank or how the pics appeared on the page?

09/14/2016, 09:40 PM	#9199
sleepydoc Registered Member Join Date: Oct 2011 Location: Minneapolis, MN Posts: 3,907	The steady state level in the overflow is determined by 2 things: The level of the open channel and to a lesser extent the valve on the siphon. Consider how the Bean is designed to operate - the siphon takes the majority of the flow with the open channel taking the flow above what the siphon can't handle. Imagine that the siphon is established and the siphon flow and the return pump flow were perfectly matched, the water level could be anywhere between the inlet to the siphon and the ledge of the open channel (the point at the top of the inverted U where the water just makes it over the top to go down the standpipe.) Now consider that the flow is slightly greater than the siphon can handle. The water level will rise until it starts making it over the ledge of the open channel. The more flow the open channel needs to handle, the higher the water will rise. This will continue until the flow in the open channel is 'maxed out,' at which point the water level rises to the level of the dry emergency. For an external overflow like you describe, you don't necessarily need the inverted U, but if you omit it, the opening to the siphon pipe needs to be far enough below the surface that it doesn't entrain air. As Outdrsyguy1 noted, the further down in the box the siphon opening is, the more water will drain out when the power is cut. As long as your sump can handle the volume this isn't an issue; it should start back up again either way, but if you are interested in minimizing the amount that drains down, the inverted U will allow the opening to the siphon channel to be placed higher in the box than a straight open pipe. I agree with Floyd - the pipes are too high in the box __________________ ~~~~~~~~~~~~~~~~~~~~~ 120 gallon, coast to coast overflow w/beananimal overflow. Waveline DC 10000 II return pump, 40 gal sump, Octopus XS200 skimmer, T5 lighting

09/14/2016, 11:09 PM	#9200
Outdrsyguy1 Registered Member Join Date: May 2013 Posts: 81	thanks a ton everyone, i need to tweak it and see how things go. I'll drill the siphon line hole and install the fittings and move things down a bit.