# Nano overflow...



## zozo (20 Dec 2017)

Don't have to say, but do it anyway, i'm a sump filter fan.. And i notice people tend to think it's difficult and expensive and to large and all. But nothing is further from the truth, most people having a sump likely will agree and confirm. Now i was thinking of a nano sump for a nano thank..  And thought lets create minimaly distracting and a small, cheap as possible overflow anybody can make and see how it performs.. I was thinking at least 250 l/h performance so you could reach a 10x turnover with a 25 litre tank. And create a sump out of a 10 litre bucket if yuo like..

I took the principle of the standard overflow box available in the LFS or for us Europeans via Ebay since most of them are made in USA, sump country No.1. Smallest available 800 gallon capacity. $10 per 100 gallon.. It's not the first time this is build, seen it before on utube, all tho the versions i've seen where exeptionaly crude and still a bulky build. I sized it down even further and neated it a bit up..






This is the crude diagram in idea of what is readily available for us in any hardware store. Standard PVC components.




This is the actual overflow as i build.




Didn't have any knees available at the time so i did bend the 16mm pvc tube in a U tube. For the rest i think i don't have to explain all the used components, I think the pic speaks for itself. If not please ask.. 

the only thing i used differtly instead of a T in the tank side. It is 25mm PVC tube and a filter inlet basket of a cheap SUNSUN filter in/outlet set. I was only using the outlet spray bar in my aquariums. So i have a few inlets to play around with. Funny is these baskets are excactly 25mm and fit snugly over the tube. Did cut a hole in the top, sanded it a bit larger to make it snugly fit a 16mm pvc tube and it works like a charme.. It can slide up and down as well to change the drainage in the tank. And it saved me a T and a reducer. 








The left hand side is the in tank overflow, this actualy doesn't need to be glued if it fits snugly, it will be submersed all the time anyway.. The right hand side is the outside tank water lock. The reducer on top of the T obviously has a retainer bumber inside, this needs to be sanded out so the u tube can be sunk all the way down into the water lock.. You only need to glue the reducer into the T. The tube into the T and the cap on the tube. The water never reaches the top and if the U tube aint glued it can change possition 180°. And makes it possible to take all apart for cleaning. And this small size you don't need to prime it.. Dip in a bucket with water take it out and it's ready to run. Put a cupling at the outlet end to go on to the sump..

Test run! Approximately it performed better than expected.. According my stop watch calculations it drains about 300 l/h.  I created a split drain pipe bellow my 100 litre low tech tank, so i could sufice with 2 of these small ones to reach my 6 x turn over.


 So obviously it works pretty well, why not?.. It's a super mini overflow box.. And you can make it any size you like, go bigger if you want it in a bigger tank.. I guess can't get it much cheaper than this..

Have fun.


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## rebel (21 Dec 2017)

Hi Marcel, great build as usual. 

Are there concerns about flooding or other issues if siphon is broken?


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## zozo (21 Dec 2017)

rebel said:


> Hi Marcel, great build as usual.
> 
> Are there concerns about flooding or other issues if siphon is broken?



Tank you Rebel.. 
I've been sumping around now for little over 2 years and playing with diy overflow syphons. Made a few from clear pvc to see what  happens inside. And noticed the major design flaw creating syphon brakes is water fall speed and vacuum. This mainly occurs when a pipe is to small in diameter in relation to it's length. E.g. (pic from the net)

This concept:



That's quite a lenght of tube if this is made to small to make it less bulky, say 16mm tube, than the fall speed in relation to it's drain capaicity is rather large.. Than the fall speed will suck airbubles all the way down to the 1st U turn and end up in the 2nd u turn. Could accumilate there and syphon is broken. Or the fall speed creates a vacuum and suckes the bubble through making it slurp and burb.  The only way to reduce this is to put a valve at the Drain to Sump end and reduce the fall speed and also it's capacity. And a valve is an extra dirt accumulating obstruction in need of constant readdjusting.

So the major design flaw in this is making the falling down route longer than the rising tube in the tank.  As shown in the diagram Drain to Sump point is lower than the 1st U turn in the tank. Actualy they should be the same length and the connection should be open into a wider drain pipe. A bigger mistake is keep it a closed route all the way into the sump, creating evenmore suction at the syphons inlet due to greater fall speed of the water.

Same as if you would make my above design like this. It will fail, the fall speed (volume/mass) is greater than the suction (volume/mass) inside the tank. this syphon will break if the pump stops.





Point is to reduce fall speed is to make the syphon as short as possible and evenly long legs in this design the 16mm syphon is only 15 cm. And still there should be used a wider drain pipe to create an open connection. Because if the route is closed to the sump where the drain pipe should be submersed to reduce noise will be completely filled with water and the flow stops it likely will create a vacuum due to the fall speed and suck empty the syphon.

Anyway this will never ever break, the fall speed weight equals the lift weight.. It might only block if it aint maintained or protected properly. And to reduce the chances of a block i prefer to use 2 drain points in the tank. If one fails the other takes over. But this is a rather unlikely what if scenario.. It never happened to me.. But never say never. 





The other advantage of using 2 smaller designed overflows is multiple drain points, it can benefit the flow distribution in the tank.. E.g having a drain right and one left.

Flooding prevention in case of a block? Nothing can be more easy to prevent. The tank has a rest volume to fill before it floods. Lets say it's a 100 x 50 tank.. Than 1 cm water level = 5 litres of water if the water level is 3 cm bellow the rim it needs 15 litre to flood. Simple elevate the pump into the sump so it can never ever drain more water from the sump than 10 litre. And your done.. Just make sure it's a pump with a thermal protection, so it stops when ever running dry and hot. But realy very unlikely to happen if everything is designed properly.

Same works other way around, if pump stops the tank will drain to the sump and the sumps water level will rise. Calculate this vulome and never overfill the sump. If all is running the sump should still be abble to hold this extra 10 litres of water drainage from the tank in case of a power outage.


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## zozo (21 Dec 2017)

Btw, you don't need to buy any excisting in outflow sets to obtain such a basket. They are available in the ordinairy PVC industry in all kinds of metric sizes.. I just don't know the english name id these buggers. Don't know what to look for.. But if we have them UK has them i'm sure..





https://www.xxlstunt.nl/assortiment/Druk-PVC/Korfen


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## Edvet (21 Dec 2017)

I liked this one too:


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## zozo (21 Dec 2017)

Edvet said:


> I liked this one too:




Yep  Seen it.. And thought this i can make much less complicated, smaller and even more suficient and probably a bit cheaper too.
In my design, there is a possibility to adjust the drain level in the tank with slidding the drain up an down. The basket protects blocking. The outlet aint fixed it can turn 180° so it makes routing more adjustable. And it can be taken apart for cleaning.. I must have been Japanese in a former life, steeling designs and improve them..  It's a 300 l/h instead of a drip..


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## kadoxu (27 Dec 2017)

What about this upgraded version? What do you think of it?



 

I drew this pic, but the idea is obviously not mine. The first time I saw this version was in one of DIY King's videos, but I've seen it in loads of places since. I like your version better, but I really need all the flow I can get with this one.


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## zozo (28 Dec 2017)

I've tried it with a box model and it didn't realy work becausse i sized it wrong.. In your diagram i assume it's a standpipe. I tried that with an oversized box. The syphon sucket the box empty faster than it could fill.. As soon as there is air comming in it breakes or it gets awfully noisy.

And till now all video's i've seen with these installed version all were noisy. This is because of the rather relative large water volume in it outside the tank and inside the tank.. It's hard to explain in laimans terms in words.. Because i'm no expert in explaining nor calculating fluid dynamics. And to make a syphon like this work flawles you need to know the physics and math formulas to calculate it. So i try it like this.

A is your diagram, now if your draining water from the tank, the grey area in the stand pipe will be fillled with air because of the fall speed/drain capacity. The purple represents the tankwater volume running over into the standpipe. A larger fall seed in the tube will create a deeper suction in the stand pipe. If the force of the falling water is greater than this capacity it will get all the way to the bottom of this pipe and suck in air or break. Making them from clear tube, shows and helps understand what happens inside these things.

Water also wants to communicate with gravity (communicating vessels) See the red line in A and B. Even under force water wants to equalize to this if it can't due to force, these forces work against eachother it will make the waterlevel in the syphon fluctuate up and down all the time. So the legs should be best in same lenght. See the leg lenght and red line in B.

The issue with these syphons is they are noisy if working at full speed and sized incorrectly even louder. The ! volume is way smaller than the ? volume. No valve at the end to regulate the fall speed of that ? volume is a risk it breakes or get noise sucking airbubbles in.The drain capacity of the standpipe should be greater or equal to the speed force or mass created by falling water in ?. The mass/volume of ! should be equal to the force in ?.. If it isn't ! will be sucked out.





Even if you are the wizkid able to calculate it propperly, with mass/volume/friction/fallspeed by gravity etc. Than you still run into to dirt which changes all these constants. 

So what do i think, these types of syphons can be a pain in the neck.. It's make them, try them and if it doesn't meet expectations than make new ones bigger.. And if you want to size them correctly for more than 600 l/h and not be noisy. You end up with a rather bulky pipe line hanging to your tank. i tried to size them down for my 100 litre tank with a 600l/h aim. Made 2 from 16mm tube and both maybe run at a 400 l/h without making noise. Than i need a valve to reduce the suction, without valve to reduce this the diameter vs. lenght doesn't comunicate it suck in to much air. my tank is not deep enough to make them longer, so i can only up the diamter what would make them more bulky again.

Here you see the ones i have in use now. They do good are running for over 2 years. but they have less capacity than anticipated. The arrows show the water level in stand pipes inside/outside. If i would open the valves this level would lower and suck in air and get noisy or even break the syphon.




400 l/h i can do with. But want to play with some more.. So i had to make these bigger or come up with an nother even less bulky design performing beter and that is easier to maintain. And the above design seems to be in both ways regarding the previous test run..  Not yet have them in use on the tank, still missing a knee,these were sold out in the shop and because of the holidays didn't get them yet.


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## zozo (28 Dec 2017)

Oh  and for now it's just a prototype, i'll run it for a while to see if it's sized correctly for the longer term.. If it is i'll remake them from clear material to be a bit less distractive.
https://nl.aliexpress.com/item/NuoN...quarium-Water-Tank-Pipe-Tube/32832373512.html

It will make them less cheap, but i'm not in it for the money only. Also a bit for the looks and satisfaction of the diy part.


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## kadoxu (28 Dec 2017)

Thanks! That helps a lot. I think I'll try to build a couple of them and see how it works. 



zozo said:


> Even if you are the wizkid able to calculate it propperly, with mass/volume/friction/fallspeed by gravity etc.


I can't be bothered!  I'd rather have the fun of re-building stuff.


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## zozo (28 Dec 2017)

kadoxu said:


> Thanks! That helps a lot. I think I'll try to build a couple of them and see how it works.
> 
> 
> I can't be bothered!  I'd rather have the fun of re-building stuff.



That's what i thought as well when ii saw all the formulas and data required.  Since i wanted it all small for smaller than average tanks regarding sumps. I noticed with these syphons it's the height of the tank which is a limiting factor with smaller diameters. 30 cm syphon still needs about 25mm tube diameter or more to swallow all the volume at a lower speed. What's usealy to be found on the net it's for big tanks with a lot of height starting at around 250 litres minimal 50 cm height and a + 60cm syphon here the lenght makes up the volume, but makes them all rather noisy. This we don't have in small relative shallow tanks.

Good luck and post your results.


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## kadoxu (28 Dec 2017)

I don't want to take over your post, but I also don't want to create a new thread for basically the same thing... so here goes.

For my first attempt I tried 22mm pipe and 40mm for the standpipe. I made it as short as I could in order to check how much flow and noise I would get. Parts aren't glued, so I'll just replace the bigger pipes for the next build.

30cm ruler or scale... sorry about the blurry pic.




It was pretty silent, but I could only get a 200lph flow rate. I made a hole in the standpipe to have it fixed to the rest of the piping. 

The next one will have pipes with more than double the size to check how much the flow will improve.


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## zozo (28 Dec 2017)

kadoxu said:


> I don't want to take over your post,



You don't., it's not only my show.  The TT is Nano overflow.. All ideas and designs are more than welcome.  Lets rock and roll, burb and slurp.. 

It's looking good!! I guess as said before increase the fall speed will increase the capacity. Try to make this part



evenly long as the pipe in the tank, at least a tad longer, maybe somewhere in between as long it aint glued you can try things.


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## kadoxu (29 Dec 2017)

zozo said:


> You don't., it's not only my show.  The TT is Nano overflow.. All ideas and designs are more than welcome. Lets rock and roll, burb and slurp..
> It's looking good!! I guess as said before increase the fall speed will increase the capacity. Try to make this part
> View attachment 112062
> evenly long as the pipe in the tank, at least a tad longer, maybe somewhere in between as long it aint glued you can try things.


Thanks!

That's the plan! I have about 2m of pipe to play with, and I'm pretty sure 22mm won't be enough to get the 600-1000lph flow rate I'll need from this thing, as the tank is only 35cm high, but it will at least give me an idea for what's coming next.


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## zozo (29 Dec 2017)

kadoxu said:


> pretty sure 22mm won't be enough to get the 600-1000lph flow rate


Depends how it's designed. This overflow box has max. 800 l/h





See the U tube diameter it's less than 25mm  Because example the 1" / 25mm U tube diameter is for the 2000 litre version.
https://www.ebay.com/itm/Aqua-Link-...d=222641812928&_trksid=p2047675.c100005.m1851


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## kadoxu (29 Dec 2017)

Well, I have to say, I'm a bit impressed with the new test... It was really hard to prime properly inside a bucket, but in the end the 35cm pipes raised the flow rate to about 720lph.
Same 30cm ruler for scale.


 

Noise wise, I wasn't able to test it properly, as I couldn't be bothered to cut another standpipe today. Tomorrow if I have some time, I'll drill a hole in the top U part to put air line and a check valve, just to make it easier to prime, and cut a new standpipe to test it properly.


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## zozo (30 Dec 2017)

kadoxu said:


> It was really hard to prime properly inside a bucket



Hang iit in the bucket bellow the water level, than plug the outlet with your finger or close the valve by the time you have one on it.
Than suck the air out via the aeration standpipe. Lot easier if this pipe is clear pvc, than you somehow see the water level rise in it and can stop sucking before you swallow any. Than unplug the outlet and it'l start running.

And playing with these rather long distance routed designs you have to test them realy properly before putting permanently in use and trust them.. Especialy if you want it to run at the maximum possible capacity. I remember mine working like a charm for 10 days. So i thought i had a winner from the get go. But after a few days things suddenly changed and it started to burb and slurp and suddenly suck a bubble in if this stays hanging in the first U turn it lowers the drain speed. Resulting in a rise of tank water level and a lower sump level. If tank water level gets higher the pressure in the syphon changes, the bubble than might shoot through, fall speed suddenly encreases and sucks in a new bubble when tank water level lowers again. Resulting  in erratic flow behaivor, depending the size if the sucked in bubble it might break or not. 

Next thing, since its not a clear tube you are using you'll never see what goes on inside. And you are transporting aerated or gassed water, so there will be a gas exchange inside the tube over time. Tiny acumulating fishfarts etc. will stay hanging and dancing up and down in the fall tube, causing a restriction 

Till the flow stops for what ever reason e.g. you pull the power plug. Than all these gas bubbles rise and accumulate at the top making a bigger bubble - breaking the syphon or significantly lower the drain capacity.   Those liittle stupid issues you never think about but happen and change things.


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## kadoxu (30 Dec 2017)

zozo said:


> Tiny acumulating fishfarts


I giggle every time I read it... 

Priming was way easier the way you told me to do it.

So, flow rate testing is done. 750lph was the best I could get out of it, which is not bad for starters, but it only handles the first lower setting of my return pump...

I cemented the top U so I could add a check valve to suck air bubbles out (to check if there were any). It gets a few bubbles when I stop the flow, but seems to drag them down when it restarts.


 

Noise wise, it gurgles a bit as expected, but I believe I would be able to reduce the noise by adding a large cap on top of the large standpipe... I've seen someone do it on YouTube.

Anyway, I'm probably going to buy 32 and 50mm pipes and fittings to make some more tests. I'm curious to see how a short 32mm version would do.


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## zozo (1 Feb 2018)

Here it is installed  and it runs like a charme.

Split into different non glued connections, so easy to prime in the bucket and easy to install.. See red arrows.. The one bellow marks the open connection to the sumps main drain pipe. This prevents it from ever creating a vacuum..


 

Also from above barely a distraction.




Not that the other syphon was, these are clear plastic.. You see the clear 16mm U pipes in the corners run all the way down to the substrate. This is gone now and replaced with a 5 cm long piece 25mm pipe at the top.




Planning some Tiger Val in that corner anyway. Giving up on the Crypt spiralis var. shola, that still stands there but refuses to show itself. darn bugger of a crypt..
Later on, i will cover that pipe. Sand it, apply epoxy to it and powder it with grinded peat, to give it a natural look and cover it again with a short growing moss growing to it. Than it will be completely gone from view as a piece of overflow..




New sutiation from the top view  doesn't look very much different. It's still minimal as possible.




Aestheticaly and minilastic the clear ones are the best syphon i ever created.. But a hassle to clean.. This is the one still runnng for now at the other end. You can imagine it's a hassle to clean getting the wire brush all the way through and beeing so minimalistic it needs constant readjusting with the valves.




The new version doesn't have the need of a valve, it just runs constantly at the given speed and is easier to prime.. It can be taken apart in 5 different sections to clean and put back together. Tho i doubt it will need much cleaning, just in case.  Mission overflow succeeded..


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