Silent and Failsafe Overflow System

[sleepydoc]

Well, the high pressure (or back pressure or whathave you ... to not get into semantics) isn't at the top of the pipe, it is at the outlet of the pipe. ...

Rather than pressure, I think it's actually flow (which I realize is related to pressure.) Ultimately what we are interested in is the siphon standpipe flushing/purging the air so it can run efficiently and quietly. Once this happens the system settles into it's quiet, steady-state level. That takes a combination of an adequate flow rate and enough time. If the flow is high, it will flush the air through relatively quickly. At slower flows it takes more time, and if the flow is too slow it will never happen.

The pressure difference driving the water flow is related to height, but the few cm of difference in height between the top of the open channel pipe (where the water level normally peaks,) and the siphon channel intake is not enough to cause that much difference in flow rate. I think the bigger reason that having the open channel air tube occlude below the level of the emergency standpipe causes issues is because the flushing that typically occurs when the open channel begins to pull more water drops the level in the overflow to the point that the siphon channel sucks air, preventing it from ever completely purging all the air. Essentially, it doesn't have the time to purge the air before getting scuttled by more air coming in. In Gorgok's case, it is either not entraining air, or not entraining enough to prevent the siphon channel from purging all the air.

Got a problem getting the system to work? Is it sluggish and/noisy? Just doesn't seem to be right?? Ask sleepydoc, his keyboard does not have a mind of its own like mine does... :bounce2:

Idunno - sometimes it's got a mind of it's own! :lol2:

In terms of the 'trip' order, I'm trying to think if having the open channel tube occlude below the level of the emergency drain would alter the safety of the system, apart from any startup issues. If the siphon becomes partially or completely occluded, the open channel would increase it's flow, first becoming noisy, then, if the level rose enough to occlude the air tubing, it would transiently convert to a full siphon, rapidly dropping the level in the overflow and cyclically flushing. If both the siphon and open channel became occluded for some reason and the open channel wasn't able to clear itself, the emergency would have to take over, with the main issue being whether it could handle the flow before the tank's water level got too high. That is ultimately a factor of the pipe diameter, the flow, and the vertical distance between the rim of the tank and the top of the emergency standpipe.

Contrast this with the situation where the air hose is above the emergency pipe: the water level would rise and the emergency would kick in. The water level would continue to rise until either the two pipes could handle the flow, or the air tubing gets occluded and the open channel converts to a siphon. In the case where it is completely occluded, I can't see any difference.

 

[sleepydoc]

Found this thread....

http://www.reefcentral.com/forums/showthread.php?t=1814606

It indicates that a 1.5" SCH40 PVC at full siphon should handle 1719gph at 4ft drop... if I am reading that right. It also indicates to derate that 15%... so 1461gph.

I am building a 1.5" BeanAnimal.... the question is how much flow can it handle safely??

1461gph seems low compared to other things I've read. If you assume the Emergency's function is to replace the Full Siphon in case it blocks... I'd allocate 0 gph to it. The Open Channel should be at 50% max I'd guess. The question is what's the max for an Open channel 1.5" PVC at 4 ft drop???

I am guessing here.... but I am doubting it'd get to full siphon and not be sucking air since it is relatively high.... if full siphon is 1461gph..... let's guess the max is 1000gph. 50% of that is 500gph....

Thus, a 1.5" Beananimal should handle roughly 2000gph and still be able to accommodate a clogged full siphon without overflowing.

Is that right??

M

What is your goal flow rate? a 1.5" pipe will easily handle 1800 gph. The problem with trying to calculate pipe flow rates is that the flow is dependent on the resistance of the pipe, and the resistance of the pipe is dependent on the rate of flow. As I'm sure you realize, this is a differential equation and much more difficult to solve. Add on top of that the fact that there are many estimates and assumptions and you realize that any calculation will be an educated guess at best.

Regarding your questions of flow rates in the open channel, are you meaning total possible flow rates, or quiet flow rates?

 

[uncleof6]

Assuming gravity feed and/or suction side of the pump: 2100gph with minimal pressure loss and noise. Friction loss climbs beyond that, and may need a larger pipe size. Under pressure >~100psi the capacity is ~7500 but it may well be hammering itself apart. There is a "terminal velocity," for gravity feed, my memory fails me but 5500gph seems to stick in my mind. Don't quote me on that. It hardly matters, as at a point much lower than that, you are just fighting friction losses. A 1.5" durso will handle around 350gph before it starts acting up.

I don't know where the 50% things and some of your other figures are coming from, however, a Bean system as designed (on 1" bulkheads) **should** be able to hit 2 grand or better safely, depending on the pipe size and length of the drop. Over 24" at any rate. At 24", 1200gph is not to be unexpected with 1" pipe and ~1500 or so with 1.5" pipe. These are approximations, as there are numerous variables involved.

The limiting factor is the bulkhead, so all calcs should be done with the bulkhead actual size, rather than the pipe size.

Practically speaking, I would use 2000gph as a "max" and target around 1500 on the stock system, even though we know it will most likely do better. If wanting to go to 2000 or beyond, upgrade the bulkheads to 1.5"; and if wanting to really take advantage of the capacity increase, up the pipe size to 2".

On the open channel 500gph is a bit ambitious, and will not produce pleasant results. If we just accept that 350gph is where the problems will start, we have an idea where we need to go <200 or so gph, to give us a wider bandwidth, before it starts acting up. The MAX on the open channel would be identical to that of the MAX on the main siphon. Assuming the sizes are the same. Since when running, the main siphon is partially closed, the MAX on the open channel is actually greater than the main siphon. Same would go for the dry emergency. Remember when needed, the open channel no longer functions as an open channel. When the open channel trips (last resort) it clears the overflow box rather quickly.

 

[NASAGeek]

My "goal flow rate" is 10-15 times turn over of the display tank. 210g tank... minus sand and rock.... 3" of sand... 250lbs of live rock. Not so sure how to estimate the lost water volume of 250lbs of live rock.... so I am estimating that if I target 2000gph, I'll be in the 10-15 times turnover range.

I absolutely do NOT want ANY risk of overflow or flooding. I "feel" like at a 1.5" Beananimal I am covered well and fault tolerant.... but I wanted to check.

I've got a separate thread asking for feedback on the right return pump.... I am thinking Jebao 12000 to get me the 2000gph at 4-5 ft head. Even that's an estimate.... because of elbows in the pipes and such causing increased resistance.... I'd rather "oversize the pump" and dial it back... and the Jebao 12000 seems on the boarder of being able to do it.

Feedback appreciated. Thanks
Mark

 

[NASAGeek]

Assuming gravity feed and/or suction side of the pump: 2100gph with minimal pressure loss and noise. Friction loss climbs beyond that, and may need a larger pipe size. Under pressure >~100psi the capacity is ~7500 but it may well be hammering itself apart. There is a "terminal velocity," for gravity feed, my memory fails me but 5500gph seems to stick in my mind. Don't quote me on that. It hardly matters, as at a point much lower than that, you are just fighting friction losses. A 1.5" durso will handle around 350gph before it starts acting up.

I don't know where the 50% things and some of your other figures are coming from, however, a Bean system as designed (on 1" bulkheads) **should** be able to hit 2 grand or better safely, depending on the pipe size and length of the drop. Over 24" at any rate. At 24", 1200gph is not to be unexpected with 1" pipe and ~1500 or so with 1.5" pipe. These are approximations, as there are numerous variables involved.

The limiting factor is the bulkhead, so all calcs should be done with the bulkhead actual size, rather than the pipe size.

Practically speaking, I would use 2000gph as a "max" and target around 1500 on the stock system, even though we know it will most likely do better. If wanting to go to 2000 or beyond, upgrade the bulkheads to 1.5"; and if wanting to really take advantage of the capacity increase, up the pipe size to 2".

On the open channel 500gph is a bit ambitious, and will not produce pleasant results. If we just accept that 350gph is where the problems will start, we have an idea where we need to go <200 or so gph, to give us a wider bandwidth, before it starts acting up. The MAX on the open channel would be identical to that of the MAX on the main siphon. Assuming the sizes are the same. Since when running, the main siphon is partially closed, the MAX on the open channel is actually greater than the main siphon. Same would go for the dry emergency. Remember when needed, the open channel no longer functions as an open channel. When the open channel trips (last resort) it clears the overflow box rather quickly.

My "50%" numbers were TOTAL guesses because I knew it'd be significantly derated but had no idea how much. My bulkheads are 1.5" bulkheads because I immediately saw that as the limiting factor. I haven't plumbed it yet... so upgrading to 2" pipe around a 1.5" bulkhead is easily accommodated now. I can do that.

 

[NASAGeek]

I just feel the need to express my gratefulness to the ReefCentral community.... different threads... different folks responding.... but I REALLY appreciate folks sharing the knowledge and advice to help me be successful.

THANK YOU
Mark

 

[sleepydoc]

My "goal flow rate" is 10-15 times turn over of the display tank. 210g tank... minus sand and rock.... 3" of sand... 250lbs of live rock. Not so sure how to estimate the lost water volume of 250lbs of live rock.... so I am estimating that if I target 2000gph, I'll be in the 10-15 times turnover range.

I absolutely do NOT want ANY risk of overflow or flooding. I "feel" like at a 1.5" Beananimal I am covered well and fault tolerant.... but I wanted to check.

I've got a separate thread asking for feedback on the right return pump.... I am thinking Jebao 12000 to get me the 2000gph at 4-5 ft head. Even that's an estimate.... because of elbows in the pipes and such causing increased resistance.... I'd rather "oversize the pump" and dial it back... and the Jebao 12000 seems on the boarder of being able to do it.

Feedback appreciated. Thanks
Mark

Keep in mind that the '10x' flow rate that gets thrown around is for total flow - it doesn't all have to be going through the sump; power heads can add to it as well.

The sump flow needs to be adequate to keep the water well-circulated so skimmers and other filtration equipment can work well, heaters/chillers can properly regulate water temperature, and surface skimming by the weir is adequate.

On top of that, the amount of flow necessary also depends on the type of tank - a FOWLR tank needs less flow, a tank full of SPS will need more.

 

[NASAGeek]

Yeah, I know that.... I've found that "more" is better in some things. More water volume in the system for a fixed bio-load is always good.... and I've found more flow is darn near always good.... as long as it's not extreme. Rock obstructions... all kinds of things obstruct flow... so I always oversize a bit.

I am also a bit worried on my skimmer set up. I have a display tank (210g), refugium (120g), and sump (40g). The way it's plumbed, the refugium and the DT return to the sump.... but I have the skimmer in the refugium. Therefore, proteins and crap from the DT need to go into the sump... and get pumped from the sump into the refugium in order for the protein skimmer to "get them". Having the protein skimmer in the sump just doesn't fit. I know that's not optimal.

I'll have filter socks on the returns in the sump. Changing those regularly and keeping them clean will be key. I think this'll work. I had a similar set up with a 120g DT, 55g refugium and 40g sump and it worked great.

Bottom line is that I want high flow in the DT.... turn over and power heads..... keeping that water moving and getting it into the refugium and skimmer as many times an hour as possible is important.... because in this set up, I am recirculating "dirty" water from the sump back into the DT that hasn't passed through the refugium and skimmer at any moment.

I couldn't figure out any effective solution to link the three tanks otherwise though....

Mark

 

[uncleof6]

...

Pressure is tricky. Even when I am talking about it, I don't really want to be talking about it. In a closed pump fed piping system, the pressure is constant through out the system, and the only thing that changes is the velocity/volume of flow. Low pressure = high volume, high pressure = low volume. Seems somehow backwards, but is what it is. Reason number 1 for upsizing the outlet pipe from a pump. Suction side of the pump is different. Suction head pressure available, suction head pressure required.... getting water to "boil" in the volute and destroy the pump.

Drains more closely "mimic" the physics of the suction side of the pump. Drain lines can cavitate, e.g. large volume of water hits a restriction, and the pressure drop across the restriction when it exits the restriction into empty pipe... just like a pressure drop across the pump volute... blah blah blah...

So we have zero pressure at the top of a "siphon" and a higher pressure at the bottom, and to overcome that higher pressure we need "head height" above where the water heads down. Gravity takes over, and drags the water down the pipe, and the only concern is not getting a vortex at the top (due to the low pressure.) It really need not be more complicated than that. If something subtracts from that formula you are going to have startup issues as well as restart problems, which will increase as the friction in the pipes increases with time. (explains why it worked yesterday, but not today) Tripping the open channel too soon is not a safety concern, won't argue that. It does however, subtract from the startup formula. Too much information demonstrates that clearly, and debating it, is sorta pointless. The symptoms run from unoticeable to "oh great this thing doesn't work at all."

The open channel is the current prime target for tinkerers, and is where the most damage to system function is done. It is obviously the least understood part of the system, yet it still is the target, in the quest for "form," or whatever drives the trend. To me they are just fighting themselves. We know how to make this system work, everytime, all the time. Really, build something you know will work instead of going with a trend that thus far as resulted in very mixed results. It is not going to get much further till folks figure out that this system needs some room to work. (And I still haven't gone off topic to the aspects these "mini systems" are neglecting for the rest of the system... doin good...)

 

[LXXero]

Well, the high pressure (or back pressure or whathave you ... to not get into semantics) isn't at the top of the pipe, it is at the outlet of the pipe. At rest, the pressure at the top of the pipe will be lower than the pressure at the outlet. Yes? Atmospheric pressure vs the hydrostatic pressure at the pipe outlet. Yes? Remember, the pipe is submerged so you have atmospheric pressure + hydrostatic pressure due to gravity exerted on the fluid. Most often atmospheric pressure is zeroed out (gauge vs true pressure.) When running the same relationship exists. Low pressure at the top, high pressure at the bottom. Yes? So there needs to be a way to overcome this, or nothing happens. What? Water flowing from low pressure to high pressure?

What is needed is head pressure (head height whatever) above the point where the water starts to head down, whether that is inside a tee, a double 90, or an open pipe. Without it, the system will stay at rest till the end of time. Even though there is a point where gravity and the surface tension of water take over the bulk of the work, a certain amount of "head pressure" is required to maintain the running state, or the system will return to a rest state.

The low pressure is easily observed. It is shown by the vortex that forms if there is not enough head height above the inlet to the siphon. The high pressure at the outlet is easily observed by noting how hard (or how easily) it is for the system to get going.

We are not talking huge differences. However, the deeper the outlet is, the higher the pressure, and the harder the setup needs to work to get going. (More head height is needed.) And yes, if the outlets are too deep in the sump, and there is not enough head height to overcome it, the system will fail to start, it simply does not matter what the upper topology of the system is. Whether that notion is liked or not, it is precisely what is going on. Ells where used in the model, and all of the systems I put up (~200+) and the reason for the ells is to reduce the height of the water column needed to maintain the system in a running state without sucking in air. I am not going to get into a debate regarding the relative merits of top end topology, all things equal the difference is not significant enough to really be concerned with, other than water height requried to maintain the siphon.

I think you are right in that there could be a depth of the tube in the sump that would simply prevent the siphon from starting. Changing the top-end topology won't eliminate this problem entirely, but I do find that not having the tension of that air bubble up top, greatly reduces the risk of it not starting, regardless of how deep that tube is (like, it might add enough pressure that even 5" under water is fine, by simply not having those 90s, don't quote me on that, i'm just using it as a "what if" scenario.) Now i'm not saying it'll work if you plumbed it to the bottom of your sump, I'm just saying that it seems to increase the safety margin by a fairly large amount.

On the other hand, I just spent today adjusting and tuning my 60 cube's herbie setup after watching my video again and thinking over some of your comments regarding how these systems are supposed to start up, and you were totally right, too, it wasn't starting up correctly, as it kept using the trickle/open channel far too much, and it wasn't putting enough pressure on the siphon line to get the siphon moving, at least, not all the time.

Mind you, this does have the double 90s, and i never had this issue on my 120G which doesn't have those. However, a simple strainer on this tank is likely not going to suffice, as it requires setting the level in the weir pretty low to do that without venturi, which is really noisy in that internal overflow box (waterfall effect) and in an external overflow box, the weir isn't nearly as deep, so water-falling water wasn't a problem, but it's looking like i'm gonna need the double 90s to keep things silent in the 60 cube. Ultimately, I raised the durso's height, and I did cut down the tube in the sump as well so it's about 1/2" below the water in the sock chamber, and this did solve the problem. Although now with the siphon fully closed, my water level gets pretty high, like half inch from the top of the rim. I think I'm OK with 1/2" given that the durso is actually handling the full flowrate of the pump with the siphon fully closed, and other than being loud, it functions fine that way. Oh yeah, and I finally cut that 12' of return tubing down...and there is definitely way more flow now, probably went from being 1/2 up the teeth to like 3/4 instead. Still not maxing it out though believe it or not, but it's getting closer to being able to the more i optimize the flow rate on this thing. I suspect if i up it to 1" all the way, I might be cutting it a little close, though. Pretty much tempted to stay with 3/4 just to purposely reduce my pumps flow rate into "Safe" margins for this tank's plumbing.

LOL I also found a paper towel I left shoved into my union to prevent glue dripping out....still in the union, somewhat attached to the pipe LOL. ooops! Cleaned all that up, lol. So yeah, in my last video of that system running, there was totally a paper towel blocking most of the siphon drain line and it was still flowing fine. Heh, unintended blockage test?

There is a great difference between draining water, and this system working the way it should. Watching you-tube videos is a double edged sword. How does one know if what one is watching is actually working right or not... videos are not a good source of information, generally they are more self-serving than anything else. That begs the question how would I know...

Over the years, and dealing with hundreds of "issues" posted here, a very short list was seen of possible things that could go wrong. All of them flaws in the implementation; a failure to follow the simple instructions, is what it really boils down too. Engineers love to fix things till they break; DIYers love to tinker with stuff, it is almost an obsession; Person A needs to outdue Person B; Person C needs to outdue both A and B. Persons D and E don't have minute 1 in experience, but they have something to say, that is only repeating what Person F and G said... Toss in some cognitive dissonance by as you put it "armchair scientists" (I don't own an armchair... seems i missing out...) and you have hundreds of posts going over the same material time and time again, (e.g. we have a big mess) that has only one possible conclusion: It works as designed. It is demonstrable, and repetitive (probably in the thousands of systems now) There is one set of circumstances in which the system works properly. There is tolerance in the system, by design, (it is not a rocket) however if modifications move the system out of the "neat little package of circumstances" it will probably drain water, but it can hardly be said to be working properly. (restart failure is a good clue... and that is 100% an implementation flaw.) Rather than fix the problem, or admit that the modification was not such a good idea, the hunt for a work around begins... well here we are 10 years later, still going over the very basics of how the system is supposed to work, and why it doesn't... but what really puts the cap on it is "Xgph without issue," really, need to get a flow meter involved, because the pump (despite the idealized flow curve) isn't even capable of doing that given the installation... (not speaking of anyone, or any pump, in particular) :wave:

Haha, truth be told, it's the internet, so to some extent, it's to be expected that people will just post questions that have already been asked and answered 1000 times....and just not do the research ahead of time, lol. This might be an amusing read, if you've never seen it, "how to ask questions the smart way"
http://www.catb.org/esr/faqs/smart-questions.html

if only everyone did that right? lol

I can't find fault in trying to minimize the form. However, there is a point where it just goes too far. And we are at that point. (past it most likely) We lose sight of other important aspects of the system overall (even if the drain system works perfectly.) Aspects that we spent "years discovering," that are practically completely ignored/dismissesd out of hand. (aspects outside the scope of a thread concerning a simple drain system.)

Got a problem getting the system to work? Is it sluggish and/noisy? Just doesn't seem to be right?? Ask sleepydoc, his keyboard does not have a mind of its own like mine does... :bounce2:

i've always been a "KISS / keep it simple" kind of guy, not just with fish stuff but with programming and electronics as well, occam's razor is another good one, lol. if there are parts that can be simplified without reducing the safety margins then i'm all for it, but knowing where things can be simplified is the hard part,on my 120G, using that strainer works great in the external box, but on the internal weir in my 60 cube, it's now clear a strainer may not work. If you'd asked me a week ago, I'd say strainer all the way, but it's clearly not going to work in every scenario, this is where experience can come in, and knowing just how the system is supposed to run is very important in that circumstance.

 

[uncleof6]

Keep in mind that the '10x' flow rate that gets thrown around is for total flow - it doesn't all have to be going through the sump; power heads can add to it as well.

The sump flow needs to be adequate to keep the water well-circulated so skimmers and other filtration equipment can work well, heaters/chillers can properly regulate water temperature, and surface skimming by the weir is adequate.

On top of that, the amount of flow necessary also depends on the type of tank - a FOWLR tank needs less flow, a tank full of SPS will need more.

Disagree sleepy. That 10x is not "total" flow, as the fact is there is no such thing as "total flow," that is hobby speak. Flow through the sump, and so called "flow" in the main tank do different things. These two flows are not supplementary, or additive. They cannot be, they do different things. Main flow drives the life support system, the "in tank" flow keeps the tank well mixed vertically.

This concept is as old as open systems have existed, as vertical mixing in a tank fed from the top, with removal at the top, need to be vertically mixed. Power heads were employed to accomplish that vertical mixing. NO thought was given to adding this to the primary flow. I know, I was there...

10x is an arbitrary number. 5x is an arbitrary number 20x, 40x, 100x, are all arbitrary numbers. We cannot even dream about approaching the "flow" rates around a natural reef. 5x was dreamed up by marketers relating to undergravel filter plates; promoted by authors such as Spotte. The number was pulled out of someones back pocket. But what we learned by running these systems, is the harder we pushed them, the better they worked. Example is I had an 80 gallon tank, with a march pump pushing close to 5x, with UG plates (long time ago.) The system was poor, constant problems. Bad luck, lack of experience, temps to high, too low, inefficient (actually non-existant) skimmer.... I reworked it, put in an LG TE-5MD, pumped it up to around 1k and the tank came to life... which left the only real issue the buildup of dissolved organics... you tell me...

What is at work here is the concept of a multi-pass system, as opposed to a single pass system (of which there is only one such sub-system in an aquarium system: the skimmer.) The faster you run a multi-pass system, the better it works. This has been known for a very long time. It is oddly a missing concept in current aquarium pursuits; stuck in a time that has long past.

Think about it: what good does it do to have all this wonderful "flow" in the tank, but have a whimp return pump, so the stuff stays in the tank a great deal longer, causing problems? The drill is get it to the top, and get it out of the tank where the skimmer and/or RDSB (whatever) can have at it, and getting oxygenated water to every crook and nanny of the tank... one of the first things I note in a failing system, as well as "successful" systems, that just lack that umph... The faster this happens, the better everything goes. Lower oxygen demand, higher oxygen levels available (this is measurable, however it has been deemed "unecessary") lower dissolved organic levels (not easily measured at the hobby level) Cause of old tank syndrome: dissolved organics, not inorganic phosphate... blah blah blah...

Nothing has really changed since we learned these things. More gadgets that attempt to make up for lack of husbandry have come about, and the quality of rock available has hit rock bottom (pun intended.) It does not do what it used to. One would think, that what got this hobby off the ground, certainly should be a good plan today, and the actual reasons we did something, ought to be the same reason they are done today... not for some invented reason the origin of which will probably never be established... more science, more thought; less technology and less myth....

Now you done it: got me off on a tangent.... Drains anyone?

 

[uncleof6]

Yeah, I know that.... I've found that "more" is better in some things. More water volume in the system for a fixed bio-load is always good.... and I've found more flow is darn near always good.... as long as it's not extreme. Rock obstructions... all kinds of things obstruct flow... so I always oversize a bit.

I am also a bit worried on my skimmer set up. I have a display tank (210g), refugium (120g), and sump (40g). The way it's plumbed, the refugium and the DT return to the sump.... but I have the skimmer in the refugium. Therefore, proteins and crap from the DT need to go into the sump... and get pumped from the sump into the refugium in order for the protein skimmer to "get them". Having the protein skimmer in the sump just doesn't fit. I know that's not optimal.

I'll have filter socks on the returns in the sump. Changing those regularly and keeping them clean will be key. I think this'll work. I had a similar set up with a 120g DT, 55g refugium and 40g sump and it worked great.

Bottom line is that I want high flow in the DT.... turn over and power heads..... keeping that water moving and getting it into the refugium and skimmer as many times an hour as possible is important.... because in this set up, I am recirculating "dirty" water from the sump back into the DT that hasn't passed through the refugium and skimmer at any moment.

I couldn't figure out any effective solution to link the three tanks otherwise though....

Mark

At any given moment in time, more water is bypassing the skimmer, than is actually going through the skimmer (this is regardless of flow rate, high low, same same. Such things in a fast moving multipass system should not be a concern. If one is running the main flow through a skimmer (gravity fed; bad move) this is a bit different. We can't get all the organics out with a skimmer, most cannot be removed with this method; and really can't get them all out any way. They are being produced as we pull them out.

The value of "refugiums" is very questionable. Many high end systems are eliminating them completely, opting instead for RDSBs (nothing but sand and bacteria) on a seperate pump. Works good, lasts a long time. To really be worthwhile, "fuge" should be > than half the DT tank so...

...Refugium is another display tank, and as such should be plumbed to a commonn sump with the DT, so linking three tanks is really not a big deal to accomplish. With a good pump, they can run on a single pump. I haven't followed your system closely, so hoping I understand your post clearly.

On a positive note, the things you are talking about are good concepts, but the skimmer should be in the sump--not the refugium. The two do not work well together: production and export together? Naw the lesson: "refugia" in the current popular implementation, are high production areas, not export areas, and never were export areas. Multipass good; multi-purpose: not good. A refugium is really good at providing bio-diversity, which is excellent for any system. (not contradicting, just typing in random order...)

 

[jason2459]

Awesome conversation. All I know is my system is doing great jumping from the 750gph return to the 1400gph I'm at now. Plus the two gyres at 100% my tank is a mixing machine. Many tanks can handle a lot more flow then they have.

I know nothing at all about fluid dynamics but practically every person I have seen that messes with the siphon and what it feeds into ends up having issues or having to adjust it time and time again. Latest one was trying to have the siphon feeding into a roller mat filtering system. Initially seemed to work. Then didn't. Then worked. Then didn't. Not really the goal of using a bean animal drain system.

I would not suggest anyone mess with the basic design, particularly how they feed into the sump, and particularly the siphon. Something will give. Silent operation, reliability, or redundancy one or more of those will fail.

 

[RWEngineer]

Found this thread....

http://www.reefcentral.com/forums/showthread.php?t=1814606

It indicates that a 1.5" SCH40 PVC at full siphon should handle 1719gph at 4ft drop... if I am reading that right. It also indicates to derate that 15%... so 1461gph.

M

That chart shows flow from 1 inch to 12 inches.

Try this calculator

http://www.beananimal.com/articles/hydraulics-for-the-aquarist.aspx

 

[jason2459]

Found this thread....

http://www.reefcentral.com/forums/showthread.php?t=1814606

It indicates that a 1.5" SCH40 PVC at full siphon should handle 1719gph at 4ft drop... if I am reading that right. It also indicates to derate that 15%... so 1461gph.

I am building a 1.5" BeanAnimal.... the question is how much flow can it handle safely??

1461gph seems low compared to other things I've read. If you assume the Emergency's function is to replace the Full Siphon in case it blocks... I'd allocate 0 gph to it. The Open Channel should be at 50% max I'd guess. The question is what's the max for an Open channel 1.5" PVC at 4 ft drop???

I am guessing here.... but I am doubting it'd get to full siphon and not be sucking air since it is relatively high.... if full siphon is 1461gph..... let's guess the max is 1000gph. 50% of that is 500gph....

Thus, a 1.5" Beananimal should handle roughly 2000gph and still be able to accommodate a clogged full siphon without overflowing.

Is that right??

M

It will handle a lot more then 2000gph I would imagine.

My internal weir was my limiting factor otherwise I'd be pushing more then 1400gph through mine. All 1.5" plumbing. Someday I will get a new tank and get a coast to coast.

I'm pushing 1400gph through and I have to have the siphon valve well over half closed. My siphon is now almost a straight drop. I had start up issues with it purging out the air to fast and sucking in some more a d would do this a few times before full operation. I could leave it like that or I figured I could put some bend in near the sump or restrict it better then my ball valve.

What I tried was reducing to 1" just before the sump as I had all the parts and couldn't hurt to try. It worked perfectly. At least for now and will see long term. Its been a little over a month now running like this. Silent startup and even my shutdown is a lot more quite then even when I was running at 750gph.


You can see how closed the valve is now and it was a lot more when all 1.5"

Just barely into the water at normal running operation. That is the lowest that sump chamber will allow that water to get.

 

[nanomania]

those teeth actually do look really tall. You might be OK with that. Worst case scenario, you could bust out a few teeth if the flow was too much...

Problem is that the thickness if the acrylic us only 4mm.

Sent from my GT-N7100 using Tapatalk

 

[LXXero]

Problem is that the thickness if the acrylic us only 4mm.

Sent from my GT-N7100 using Tapatalk

don't think that should be a problem in and of itself? what concerns you? just worried about breaking it?

 

[uncleof6]

I think you are right in that there could be a depth of the tube in the sump that would simply prevent the siphon from starting. Changing the top-end topology won't eliminate this problem entirely, but I do find that not having the tension of that air bubble up top, greatly reduces the risk of it not starting, regardless of how deep that tube is (like, it might add enough pressure that even 5" under water is fine, by simply not having those 90s, don't quote me on that, i'm just using it as a "what if" scenario.) Now i'm not saying it'll work if you plumbed it to the bottom of your sump, I'm just saying that it seems to increase the safety margin by a fairly large amount.

On the other hand, I just spent today adjusting and tuning my 60 cube's herbie setup after watching my video again and thinking over some of your comments regarding how these systems are supposed to start up, and you were totally right, too, it wasn't starting up correctly, as it kept using the trickle/open channel far too much, and it wasn't putting enough pressure on the siphon line to get the siphon moving, at least, not all the time.

Mind you, this does have the double 90s, and i never had this issue on my 120G which doesn't have those. However, a simple strainer on this tank is likely not going to suffice, as it requires setting the level in the weir pretty low to do that without venturi, which is really noisy in that internal overflow box (waterfall effect) and in an external overflow box, the weir isn't nearly as deep, so water-falling water wasn't a problem, but it's looking like i'm gonna need the double 90s to keep things silent in the 60 cube. Ultimately, I raised the durso's height, and I did cut down the tube in the sump as well so it's about 1/2" below the water in the sock chamber, and this did solve the problem. Although now with the siphon fully closed, my water level gets pretty high, like half inch from the top of the rim. I think I'm OK with 1/2" given that the durso is actually handling the full flowrate of the pump with the siphon fully closed, and other than being loud, it functions fine that way. Oh yeah, and I finally cut that 12' of return tubing down...and there is definitely way more flow now, probably went from being 1/2 up the teeth to like 3/4 instead. Still not maxing it out though believe it or not, but it's getting closer to being able to the more i optimize the flow rate on this thing. I suspect if i up it to 1" all the way, I might be cutting it a little close, though. Pretty much tempted to stay with 3/4 just to purposely reduce my pumps flow rate into "Safe" margins for this tank's plumbing.

LOL I also found a paper towel I left shoved into my union to prevent glue dripping out....still in the union, somewhat attached to the pipe LOL. ooops! Cleaned all that up, lol. So yeah, in my last video of that system running, there was totally a paper towel blocking most of the siphon drain line and it was still flowing fine. Heh, unintended blockage test?



Haha, truth be told, it's the internet, so to some extent, it's to be expected that people will just post questions that have already been asked and answered 1000 times....and just not do the research ahead of time, lol. This might be an amusing read, if you've never seen it, "how to ask questions the smart way"
http://www.catb.org/esr/faqs/smart-questions.html

if only everyone did that right? lol



i've always been a "KISS / keep it simple" kind of guy, not just with fish stuff but with programming and electronics as well, occam's razor is another good one, lol. if there are parts that can be simplified without reducing the safety margins then i'm all for it, but knowing where things can be simplified is the hard part,on my 120G, using that strainer works great in the external box, but on the internal weir in my 60 cube, it's now clear a strainer may not work. If you'd asked me a week ago, I'd say strainer all the way, but it's clearly not going to work in every scenario, this is where experience can come in, and knowing just how the system is supposed to run is very important in that circumstance.

Well, to be frank with you, your herbie is not set up correctly, nor is it really safe.

Credit to Herbie for publishing before most of using siphon system prior to his "article" even thought about putting it on the internet, and in fact this sort of drain predates the internet. He modified an existing system, to fit in a small corner overflow (form vs function.) Essentially removing the Ells, and putting it in a corner overflow. Who knows who came up with the original system idea first, could have been one person, or a hundred simultaneaously.

Siphon systems are a risky proposition. Richard Durso's standpipe was a direct response to the inherent risk of a siphon. As we all know, the Durso goes nuts if one tries to put the spurs to their system. Which left those with large tanks and high flow rates, out in the cold with the risk of a drain that did not allow air in capable of flow rates measured in thousands of gallons per hour. Long story short, it only takes once, to learn that it is "extremely unwise" to run a "siphon" system, without a dry emergency backup; repeat: A DRY EMERGENCY backup.

The definition of a "dry emergency" is a pipe that is dry, e.g. it doesn't have any water in it, in point of fact the inlet is above the steady state water level. It is extremely improbable that a dry pipe will become plugged up, occluded, have junk grow in it, or otherwise fail. There is simply not a failure mode for a dry pipe. Nothing will get sucked into it, and sea critters, as curious as they seem to be a times, won't stray too far from water. (Jumping fish and such is a different topic, and relates to poor husbandry)

A wet pipe is a plug risk. There is no way that it could not be. A little water, a lot of water, it is a risk. We can banter on and on about the statistical probabilities, but a small risk is still a risk, and the cost of damage simply is not worth the risk. Bean has had two wet pipes plug, I have had two wet pipes plug, and I am certain that we are not the only ones.

Herbie knew the "law" for running a "siphon" system, and was adamant that one MUST use a dry emergency with his modification, or they would be begging for a flood. (adding to that: or at the least a burned up pump.) The notion of using a "durso" or "open channel" did not occur till several years later, after Bean published his system. Bean is a pretty sharp fella too, and he knew the "law:" never run a siphon without a dry emergency. He was adamant about it, and failing to do so is asking for a flood or burned up pump. His words: "All three pipes must be used."

The forum "telephone syndrome" grabbed ahold of these systems, and went beyond extreme when the open channel was attributed to the Herbie, and the dry emergency attributed to the Bean. The facts are exactly the opposite. (the dry emergency predating both systems.)

So you are not running a Herbie, regardless of what many would like to call it. A Herbie has a siphon and a dry emergency. What you have is a BA lacking a dry emergency, and as such it is not safe. Not pointing out anyone in particular, but it amazes me at how frivolously the risk is dismissed. Obviously, they have never experienced a catastrophic siphon system failure, but it could happen at any moment, day or night, home or away on vacation. Sure there are things that can be done to minimize the damage, to an extent, but they involve more work, and more $$ than if the system was designed to be as safe as possible (no such thing as 100% with aquariums) at the start.

Self adjustment is very nice to have. However, since the variations in a Herbie system are not that extreme, it is not worth the risk. (slight tweaking from time to time, and dialing it in may take a bit longer.) Ambient conditions do affect these systems, but if you have extreme variations in any of these systems something else is wrong. Good drain line maintanence applies here. We had a great example of this, a couple years ago. It was not the drain system, it was the pump. Were the OP running a three pipe bean rather than a two pipe Herbie, the problem may have gone unoticed till the pump ultimately failed. I don't know the outcome of that issue...

Proper Herbie self-adjusts. Water level increases, flow rate increases. Water level lowers, flow rate lowers. It is an operational characteristic of these systems. BA has a much wider range of self-adjustment. If wanting a wide bandwidth build a proper BA, it is NOT worth the risk. One can listen to experience... or not. Up to them.

 

[NASAGeek]

uncleof6.... nice response... I read it a few times.... please grade my response and make sure I am understanding...

1) More flow, higher turn over of the DT water into the filtration area is goodness.... thus my 2000gph goal is a "good thing".... and my Beananimal with 1.5" bulkheads and 2" pipes ought handle that nicely.
2) Thus, I am creating a multipass system using your lingo... If I also add good 'vertical' mixing with power heads, I should get the water in the tank into the sump 10x per hour.
3) Question, why does it particularly matter where the skimmer is??? The "bad stuff" is in the water column regardless of what tank it is. Doesn't it really just need to be "somewhere". As long as the water column is well circulated, all the water eventually goes by the skimmer. Want to understand why it needs to be in the sump other than "convention".
4) RDSB vs refugiums... read a bunch a few years back when I was setting up my 120g and was steered away from the RDSB's. I've got the 120g servicing my 210g DT... it can be a RDSB or a fuge... it there a thread you recommend on learning about RDSB? I'll start searching and reading in the meantime.

More later, thanks
M

 

[LXXero]

Well, to be frank with you, your herbie is not set up correctly, nor is it really safe.

Credit to Herbie for publishing before most of using siphon system prior to his "article" even thought about putting it on the internet, and in fact this sort of drain predates the internet. He modified an existing system, to fit in a small corner overflow (form vs function.) Essentially removing the Ells, and putting it in a corner overflow. Who knows who came up with the original system idea first, could have been one person, or a hundred simultaneaously.

Siphon systems are a risky proposition. Richard Durso's standpipe was a direct response to the inherent risk of a siphon. As we all know, the Durso goes nuts if one tries to put the spurs to their system. Which left those with large tanks and high flow rates, out in the cold with the risk of a drain that did not allow air in capable of flow rates measured in thousands of gallons per hour. Long story short, it only takes once, to learn that it is "extremely unwise" to run a "siphon" system, without a dry emergency backup; repeat: A DRY EMERGENCY backup.

The definition of a "dry emergency" is a pipe that is dry, e.g. it doesn't have any water in it, in point of fact the inlet is above the steady state water level. It is extremely improbable that a dry pipe will become plugged up, occluded, have junk grow in it, or otherwise fail. There is simply not a failure mode for a dry pipe. Nothing will get sucked into it, and sea critters, as curious as they seem to be a times, won't stray too far from water. (Jumping fish and such is a different topic, and relates to poor husbandry)

A wet pipe is a plug risk. There is no way that it could not be. A little water, a lot of water, it is a risk. We can banter on and on about the statistical probabilities, but a small risk is still a risk, and the cost of damage simply is not worth the risk. Bean has had two wet pipes plug, I have had two wet pipes plug, and I am certain that we are not the only ones.

Herbie knew the "law" for running a "siphon" system, and was adamant that one MUST use a dry emergency with his modification, or they would be begging for a flood. (adding to that: or at the least a burned up pump.) The notion of using a "durso" or "open channel" did not occur till several years later, after Bean published his system. Bean is a pretty sharp fella too, and he knew the "law:" never run a siphon without a dry emergency. He was adamant about it, and failing to do so is asking for a flood or burned up pump. His words: "All three pipes must be used."

The forum "telephone syndrome" grabbed ahold of these systems, and went beyond extreme when the open channel was attributed to the Herbie, and the dry emergency attributed to the Bean. The facts are exactly the opposite. (the dry emergency predating both systems.)

So you are not running a Herbie, regardless of what many would like to call it. A Herbie has a siphon and a dry emergency. What you have is a BA lacking a dry emergency, and as such it is not safe. Not pointing out anyone in particular, but it amazes me at how frivolously the risk is dismissed. Obviously, they have never experienced a catastrophic siphon system failure, but it could happen at any moment, day or night, home or away on vacation. Sure there are things that can be done to minimize the damage, to an extent, but they involve more work, and more $$ than if the system was designed to be as safe as possible (no such thing as 100% with aquariums) at the start.

Self adjustment is very nice to have. However, since the variations in a Herbie system are not that extreme, it is not worth the risk. (slight tweaking from time to time, and dialing it in may take a bit longer.) Ambient conditions do affect these systems, but if you have extreme variations in any of these systems something else is wrong. Good drain line maintanence applies here. We had a great example of this, a couple years ago. It was not the drain system, it was the pump. Were the OP running a three pipe bean rather than a two pipe Herbie, the problem may have gone unoticed till the pump ultimately failed. I don't know the outcome of that issue...

Proper Herbie self-adjusts. Water level increases, flow rate increases. Water level lowers, flow rate lowers. It is an operational characteristic of these systems. BA has a much wider range of self-adjustment. If wanting a wide bandwidth build a proper BA, it is NOT worth the risk. One can listen to experience... or not. Up to them.

Well, as I said, I've adjusted it a bit since that video you saw, so it's pretty much fine now.

However, i think when we talk about risk and safety, there's a few important factors you're leaving out. This tank would have just had a single durso and a single return had I not changed it around to a herbie. It's still "safer" than that, even if i did have some trickle down what's supposed to be the dry emergency.

If I all had was a single durso, having even a single wet pipe clog would have been all it took to cause a flood. This is still better than that. Now you need 2 pipes to clog. Regardless of if they're both wet or not, 2 is still better than one.

Arguably, a herbie with a "open channel", where the open channel is taking some trickle, is no less safe than a tank with a single durso and nothing else, assuming said "open channel" can handle the full flow with the siphon closed. In fact i'd argue it's slightly less risk since again, you have 2 drains instead of one, so they now both have to get clogged. It would be hard to argue that it's more risky than just a single durso, unless the durso by itself was unable to handle the flow, in which case yes, that would be risky regardless, since even if the emergency was dry, it wouldn't actually be sufficient to handle the flow.

I do agree that it's most optimal to have the emergency be dry, though. And even oversized compared to the rest of the pipes, if possible.

Though, saying the risk is frequently dismissed is ignoring the fact that it may actually still be less risk than what the stock setup of some of these tanks looks like...just a single durso, in many cases. Reduced risk is still better than not reducing the risk at all.

A proper herbie setup can't really self adjust nearly as well as a bean with the open channel. If your flow rate decreases enough, the siphon will start gurgling, if the flow rate increases enough, then the dry emergency will kick in. You get a little bit of leeway once you've dialed in the sweet spot on a gate valve, but i agree, you get much wider margins on a full BA setup. It's just not practical to do a BA setup on a pre-drilled RR tank, without drilling more holes, anyway.