PAreefer40
New member
I don't expect anyone to do any research, as I have tried and haven't come up with anything, but does anyone know how you could use this system on a tank that's already up and running? Any suggestions?
Silent and Failsafe Overflow System
- Thread starter JohnL
- Start date
uncleof6
Active member
Probably not. Not much you can do with a running tank in the first place, without shutting it down, and emptying it. Most tanks would require modifications to run this system, and that is not going to happen with the tank in service with livestock.
I have done it, but I don't recommend others try it.
Last edited:
PAreefer40
New member
Yea, that's what I was afraid of. Well, guess I'll do it for my 90g that I will be starting in the next couple of months.
thejuggernaut
Member
I have been building an overflow box over on the acrylics page and Turbo said I have an issue with the height of my plumbing.
I see running it in two possible configurations:
This one uses a down turned P-trap on the siphon line like the traditional system shown on this thread. I haven't drilled for my vent in the open line yet, but it would be parallel with the top of the emergency, so that it would create a full siphon on the open leg in the event of a line clogging. I know this picture shows the plumbing too high in the box and that I would need to get smooth bulkhead fittings in order to lower the running level of the water in the system to make it safe.
The second system would remove all the plumbing from the siphon line so that the box would drain completely during a power outage and upon restart would slowly fill back up until the water started pouring back through the open channel. Doing it this way, I could use the lower p-trap as my open drain, and chop my emergency off so that it is lower in the tank.
I really like the idea of the second system because it does away with any start up issues related to purging of the siphon line or anything like that. The only concern that was brought to my attention would be that the siphon line might draw down air from the surface like a bathtub drain does when the water starts to run low. I plan on running around 1200-1500 GPH through it. Ideally I want the water level in the boxes to run about 3/4" to 1" below the weir in my box. That would make the running level about 2 inches from the top of the box. Is that something that would make it unsafe or is that within the envelope to give the emergency enough head room to kick in during a main line clogging? Obviously, I will do some trials on the system before I set it up, but was just looking to see what the resident gurus think, and if there are any other aspects I have overlooked.
I see running it in two possible configurations:
This one uses a down turned P-trap on the siphon line like the traditional system shown on this thread. I haven't drilled for my vent in the open line yet, but it would be parallel with the top of the emergency, so that it would create a full siphon on the open leg in the event of a line clogging. I know this picture shows the plumbing too high in the box and that I would need to get smooth bulkhead fittings in order to lower the running level of the water in the system to make it safe.
The second system would remove all the plumbing from the siphon line so that the box would drain completely during a power outage and upon restart would slowly fill back up until the water started pouring back through the open channel. Doing it this way, I could use the lower p-trap as my open drain, and chop my emergency off so that it is lower in the tank.
I really like the idea of the second system because it does away with any start up issues related to purging of the siphon line or anything like that. The only concern that was brought to my attention would be that the siphon line might draw down air from the surface like a bathtub drain does when the water starts to run low. I plan on running around 1200-1500 GPH through it. Ideally I want the water level in the boxes to run about 3/4" to 1" below the weir in my box. That would make the running level about 2 inches from the top of the box. Is that something that would make it unsafe or is that within the envelope to give the emergency enough head room to kick in during a main line clogging? Obviously, I will do some trials on the system before I set it up, but was just looking to see what the resident gurus think, and if there are any other aspects I have overlooked.
uncleof6
Active member
Looks like a flood waiting to happen to me. But folks are doing their own thing, deviating from the design, and they are welcome to do so. We cannot test each idea that comes along for flaws and possible issues. We would spend all our time testing these concepts and have no time for anything else.
The box is too small to start with. This type of system (internal/external) was designed 5 years ago. The basic layout and dimensions have been published in this thread several times. It was intended for a rimless tank, that has an external box that is 8.5" tall, and even with the top of the tank. There are no bulkheads between the internal and external. The system worked flawlessly. After all the fabrication work that went into it, the results where not worth the effort required to get there, and had I to do it all over again, I would not have bothered. It just is not worth it, and the goal (to save a couple inches at the top inside the tank) is rather ridiculous. In a nano tank where it would make a difference, this type of system (siphon) is a waste of time.
Reef savvy took the design, and chopped it up, married it up with a Glass-Holes type overflow, stuffed it in boxes that are too small, and folks are trying to follow suit. Very convenient; problem is, there are very few that actually KNOW how this system is supposed to work, as evidenced by the volumes of repetitive/identical issues and questions concerning the system, incorrect responses, and Google is not much help. I am thinking beyond RC, in case any are inclined to take that personally. You (collective) change the design relationships, and you (collective) can be fairly certain it is not going to work as it is supposed to. The trend is not moving forward, it is moving backwards to the reef ready line of thinking this system was meant to make obsolete. One of the larger reasons this system exists.
Images:
The first system does not have room to get the proper head height to start the system. The water would flood out of the box.
The second system is not going to work properly either.
Both systems would flood out of the box, before the open channel tripped to siphon, if the open channel needed to trip due to a failure/blockage.
Anything will drain water. Whether or not it will do so as it should, is another story altogether. This system was designed, built, and documented to take the guess work/thought out of the equation. 1 size fits most all situations, and it works out of the box. The only complications being those created by the end users themselves.
Floyd R Turbo
Either busy or sleeping
Uncle, I didn't know you published such a thing back a few years ago I will have to go back and look for it. But to address a few things:
Why does an external box need to be large? Isn't it possible for everything to operate properly if it's designed right? The ones that I have made work pretty much flawlessly. I agree that you need to understand the basics of the system and set it up right, you're good. The internal/external box is a design that has it's place, specifically for people who have a rimmed tank and don't want a large internal overflow box that blocks a lot of light.
1) top of ext box must be at or above the rim of the tank.
2) pass-through bulkheads must be placed such that they are submerged on both sides at all times (usually this means at the lowest point in the box) for reduction of bubbles and silent operation.
3) the external box must either A) use slip-on-flage-side bulkheads to keep the siphon and OC low in the box, or B) be deep enough to allow the plumbing to be low in the box when adapters are taken into account
4) the E-drain in the external box should be no more than 2" below the rim of the box
There are considerations to be made, but even at extremely high flow rates, a reduced size external box is perfectly fine.
Flow is not hampered by using pass through bulkheads. 2" bulkheads are 2.5+ ID and using 2 of them, zero issues with 3000+ GPH
The rate of rise of water in the external box is driven by the size of the box, that is, influent water rate and the footprint of the box, but only to the point where the water level in the box matches the water level in the tank. From that point on, the water rise rate decreases because now the water level in the tank also needs to rise in order for the water in the box to rise. However this is why it is important to have the external box even with the top of the tank - to allow for this "slow down" in the rate of rise in the ext box. This allows for a proper response time out of the 3 pipes on start up and failsafe operation.
Besides that, the only tweak in the pipe setup (that I do) is putting the p-trap or double-elbow as low as possible in the box, and then placing the OC at some point between a) matching the siphon level or b) no higher than top of E pipe (top point of OC double-elbow) and preferrably about 1/2 way between. When done like this, the siphon can be tuned to run full 100% with zero flow in the OC and there is a level range in the external box through which this will continue to operate as such without any flow in the OC, because as the water level rises in the ext box, siphon flow rate increases a bit ot compensate and vice versa. One could argue that the int/ext mod has more flexibility in the operating range because of this.
So what am I missing about the int/ext design that you say means it is a step backwards?
Why does an external box need to be large? Isn't it possible for everything to operate properly if it's designed right? The ones that I have made work pretty much flawlessly. I agree that you need to understand the basics of the system and set it up right, you're good. The internal/external box is a design that has it's place, specifically for people who have a rimmed tank and don't want a large internal overflow box that blocks a lot of light.
1) top of ext box must be at or above the rim of the tank.
2) pass-through bulkheads must be placed such that they are submerged on both sides at all times (usually this means at the lowest point in the box) for reduction of bubbles and silent operation.
3) the external box must either A) use slip-on-flage-side bulkheads to keep the siphon and OC low in the box, or B) be deep enough to allow the plumbing to be low in the box when adapters are taken into account
4) the E-drain in the external box should be no more than 2" below the rim of the box
There are considerations to be made, but even at extremely high flow rates, a reduced size external box is perfectly fine.
Flow is not hampered by using pass through bulkheads. 2" bulkheads are 2.5+ ID and using 2 of them, zero issues with 3000+ GPH
The rate of rise of water in the external box is driven by the size of the box, that is, influent water rate and the footprint of the box, but only to the point where the water level in the box matches the water level in the tank. From that point on, the water rise rate decreases because now the water level in the tank also needs to rise in order for the water in the box to rise. However this is why it is important to have the external box even with the top of the tank - to allow for this "slow down" in the rate of rise in the ext box. This allows for a proper response time out of the 3 pipes on start up and failsafe operation.
Besides that, the only tweak in the pipe setup (that I do) is putting the p-trap or double-elbow as low as possible in the box, and then placing the OC at some point between a) matching the siphon level or b) no higher than top of E pipe (top point of OC double-elbow) and preferrably about 1/2 way between. When done like this, the siphon can be tuned to run full 100% with zero flow in the OC and there is a level range in the external box through which this will continue to operate as such without any flow in the OC, because as the water level rises in the ext box, siphon flow rate increases a bit ot compensate and vice versa. One could argue that the int/ext mod has more flexibility in the operating range because of this.
So what am I missing about the int/ext design that you say means it is a step backwards?
thejuggernaut
Member
Well the box itself is 8 inches tall and sits about a 1/4" below the top of the tank trim. It sounds like from your opinion that my problem is the height of the standpipes. If I switch to slip style bulkheads, I should be able to achieve the amount of clearance I need over the top of the pipes to make it work right, which is inline with what Floyd said. When I was originally designing out the box, i made these to use for the length and width to make the box work and already had the threaded bulkheads from a previous system. This was not meant to be my final design. Thus the questions. I don't take it personally that you think it is a waste of time to modify the original design, or that it isn't worth it. However, I personally don't care for the aesthetics of the original design. The fact that the box would run the entire length of the system is an eye sore for me and this system, while more expensive and complex to make, is worth it to me. I also don't care for the shadow that the original design casts on the back of the tank. Some have tried to alleviate it by making the bottom panel transparent, but it still doesn't appeal to me. Apparently others feel the same way if they keep trying to make them in the "Reef Savvy" style, admittedly unsuccessful in some instances for lack of understanding of the drainage system. Just because the original design is perfectly functional doesn't mean it meets the criteria of "form." Either way, I appreciate you taking the time to give your expertise and answer my questions.
uncleof6
Active member
That is the step backwards, to a far less efficient design in areas that really count, to compensate for a rather ridiculous "loss of light" concern, if you know anything about how light actually behaves in water. The light loss is insignificant at the very worst, and there should not be anything below the overflow that would require light, in the first place. Follow the advice for flow characteristics that concern NOT having anything within 3 - 4" of the tank walls. The same with folks wanting to remove the 12" front to back brace on 120s in particular. Sure mess with the integrity of the tank, to save an insignificant amount of light loss.
The one I built had a 4.5" x 3.375" (height x width) internal. No teeth, full width. I have pushed it to 5k, on a 325 gallon tank. Normal operation is ~3k. It can be done, it can be done right and kept within the design criteria. But you need a larger external box, and generally a longer waterfall into the internal, than what I am seeing. The internal boxes I have seen used with this type of system are small, toothed, and a step backwards to corner overflows.
thejuggernaut
Member
For me it isn't the loss of light for the corals, it's the shadow it cast on the rear glass. Also the typical C2C box can be seen from the sides of the tank. If I was doing an in-wall tank I would probably use a C2C will a tank long external box, but mine can be seen from both sides and I don't like being able to see into the box, whether internal or external. My internal box is going to be 42" long for my 48" tank and is mostly smooth. I understand why the height of the external box is important, but why does it need to be larger in length and width? Not trying to be difficult, just trying to learn.
Last edited:
mateomarinereef
New member
If someone could please tell me how to post my own new post/thread on here I will glady be on my way. Sorry for the bother but i have tries numerous times and I can't seem to do it or it blocks me and says I am not signed in when I am already have been signed in. I am super frustrated and just want the micro bubbles to stop. Thx so much, mateo
thejuggernaut
Member
You should be able to just click the new thread topic at the top. Did you see my post earlier with the link to the herbie drain setup (post 8130)? It should be all the info you need.
uncleof6
Active member
You have a decision to make, and it is your decision, not mine. Aesthetics vs function and system health, in terms of an internal box. As far as the box being seen from the ends of the tank, well folks still flock in droves to spend their money on reef ready tanks, where the end overflow exposure outside the tank is the full height of the tank. The C2C is about function and efficiency, not about what you can or can't see from the ends of the tank.
The light loss from a C2C is insignificant, and the back of the tank being a tiny amount darker, makes we want to ask: what are you looking for back there where nothing should be? I run my lights generally around 6" short at both ends of 6 foot tanks, to make the ends a "darker" area for less "light loving" critters, as well as the back being somewhat subdued. Folks want to paint the backs of their tanks black, to make the back darker, hide pipes etc. That reduces the amount of light in the tank more than a slight shadow from an overflow box. Where you put the lights makes a difference as well, all of it makes a difference. It is an aquarium, it is not possible to make it look like a natural ocean, it only makes things hard on you if you try. We don't have the 100,000 gallon luxury of public aquariums where everything is hidden.
The height is pretty much self explanatory. In the conversation 5 years ago, it was make the external tall enough above/below the through holes to give enough vertical adjustment room to get things dialed in. This is called "tuning" the system. The water level on both sides, at the widest part of the bare 3" through holes, (center line) rather than hanging the overflow box off of bulkheads.
Longer in length so you have room in the box, and are not jamming everything together. Length and numbers of holes, make the internal and external act more as one body of water. Width less of an issue. This is becoming a case where folks are just way over thinking things, making things hard on themselves. An 18" external box on a 48" tank rather than a 12" box is a problem because? (numbers pulled at random.)
Folks are not going to notice the OF boxes, or the plumbing if the husbandry of the system is first rate, and the display stuns them into a silent stare. I think that should be the focus, rather than scratching ones head figuring out how small of a foot print can I cram this stuff into. There are advantages and disadvantages to just about everything. It is sorting out what is really important, and what just is not all that important, in terms of system performance.
This thread, and my "job" is to figure out why someones drain system does not work. The list of reasons is very short.
Needing some help. I'm reading the thread But WOW its long. I have a 300dd that I'm setting up to replace my 155 bow. My problem is the 300 has corner over flows. I want to do a c2c with a bean, but what size pluming do I use? 1.5" or 2. Can u use two siphons like 1". I want to keep the C2C a slim as possible with out hurting the efficiency. I know that it has been said you can scale up or down, but I have not seen a post that states the flow rate of 1" , 1.25" , 1.5" ,and 2"
uncleof6
Active member
Pull the corner overflows out, and plug the holes with capped bulkheads.
The width of the C2C is going to be what it is, and if you make it too small, you will regret it. The striving for the ultimate slim C2C saves a couple inches, and frankly it is not worth the work involved. I have done it, I know.
Then one each: 1.5" siphon, 1.5" open channel, 1.5" dry emergency. That is pipe and bulkhead. It may be better to run 1.5" bulkheads and 2" pipe, as there will be less friction loss to battle.
The flow rates, are based on the bulkhead size, to an extent the pipe size (friction loss from max theoretical) and the length of the drop. With each system it will be somewhat different depending. But this thread is riddled with the numbers.
1.5" bulkheads @ 3' drop will be ~4600gph max theoretical. 1" bulkheads same same would be 2041gph, 1.25" bulkheads same same would be 3189gph. You want to target 3k, so the 1" and 1.25" would be too small.
The width of the C2C is going to be what it is, and if you make it too small, you will regret it. The striving for the ultimate slim C2C saves a couple inches, and frankly it is not worth the work involved. I have done it, I know.
Then one each: 1.5" siphon, 1.5" open channel, 1.5" dry emergency. That is pipe and bulkhead. It may be better to run 1.5" bulkheads and 2" pipe, as there will be less friction loss to battle.
The flow rates, are based on the bulkhead size, to an extent the pipe size (friction loss from max theoretical) and the length of the drop. With each system it will be somewhat different depending. But this thread is riddled with the numbers.
1.5" bulkheads @ 3' drop will be ~4600gph max theoretical. 1" bulkheads same same would be 2041gph, 1.25" bulkheads same same would be 3189gph. You want to target 3k, so the 1" and 1.25" would be too small.
uncleof6
Active member
Depends on plumbing size, and how you plumb the system. Average will be 4 - 4.5" x 6 - 7", plumbed out the back.
thejuggernaut
Member
Floyd, my only question about this is that wouldn't you want the surface to be a little bit below the top of the bulkhead, so that the proteins on top of the water would still flow to the back to go down the drain. That is why I never really got why people put a durso on their open drain. With both drains running with turn downs, it is always drawing water from below the surface. A straight pipe should be better equipped to skim the proteins that are on top of the water inside the overflow. If you have the system tuned properly, it should only be a very small amount of water going down the open drain anyways. Making it completely silent.
uncleof6
Active member
But an open pipe skimming the top would suck in air. You are right, the skimming should be maintained internal to external which means for best performance, the water level should be at the broadest diameter of the hole, meaning the center line. It is hard to obtain perfection, ideally taking just the surface water down to the sump, but we do the best we can everywhere else. By virtue of the thin layer of water over the weir, taking just the surface layer into the OB, we are doing the best we can.
thejuggernaut
Member
Yea, I was gonna say. Then it collects on the surface of the sump. So then our skimmers have to be surface skimming also. If you follow the logic the the end, it gets a little un-obtainable
Floyd R Turbo
Either busy or sleeping
Unc, he's talking about the pass-through BHs on a in/ex modified
I guess you don't "have" to have them submerged, but it does highly depend on the flow rate. If you are running 3k GPH and 2x 2" PTBHs then if they are not submerged you will tend to get some vortexing and other funky water movement that can cause air to entrain into the water on it's way to the siphon, which loves to decimate air bubbles into pretty microbubbles.
If you are running a lower flow, you can probably get away with lower operating water level. But you also have a water level in your ext box that is related to the siphon and generally having the water level covering the PTBHs also means you are covering the siphon.
Any water than makes it from the tank to the overflow has the surface skimmed. Any water that is now in the overflow system is now subject to a much more volatile level of movement and thus proteins go down the drain. Think about it. How does a protein skimmer even work if it must take the water off the surface in order to remove proteins? It doesn't need to, because these are in the water column, all the time, not just the surface (surface skimming and the skimmer itself are not one and the same) but I may be corrected and am OK with that 'cause I probably explained that wrong.
Similar threads
