The Better Bell Siphon

[@Bigelowbrook]

please see the other comments about Affnan's siphon.. His will work for most applications, but it doesn't meet my needs for a very slow fill rate. Also, I've been using breather tubes for a few years and never had a problem with them clogging. Thanks!

[@Bigelowbrook]

Our 3rd most viewed video for 2013 was "The Better Bell Siphon". This video shows a little physics about how a real bell siphon operates and then a little float that I use to help guarantee it will stop. There were a lot of skeptic folks out there that didn't believe it would work, but then I started to get a lot of people writing say that this design is a life saver! 83,601 views this year (109,473 total). The Better Bell Siphon I also did a followup video about it that you can find here: How To Build a Bell Siphon

[@amazonpott6484]

I did modify the air tube. replaced flex hose w/ stainless steel tube (extra from homebrew siphon) then used a 3" piece of 1/2' copper with a cap. Fits like a glove but moves up and down easily and is stable. Have a pic, but don't know how to send it. Running for 4 days and extremely consistent. Thanks again. Love all your videos.

[@Bigelowbrook]

These are fairly standard fittings that are used for going through large plastic tanks. Here in the US we call them bulkhead fittings. A different type of fitting is a uniseal. I've also seen people take a make and female fittings used for plastic electrical conduit if the wall is thin enough.

[@Bigelowbrook]

Hi Meg! Once I put in my beds that were over 20 sq ft I started hitting this problem. Non of my beds that are 15 sqft and under have ever had this problem. I think it's from the fill rate + the rate the water is "dripping" off the stone + the overall area which makes the water level not go down fast enough to break the siphon properly. I've seen this complaint on the forums several times over the years and didn't think much of it until it started to happen to me!

[@SonOfFurzehatt]

The number of hours I've spent looking for this solution. Thanks very much for such a clear explanation.

[@Bigelowbrook]

The bed in this video is 20 sq ft (1.85 sq meter). I have another one that is 47 sq ft (4.37 sq meters). When It's all done, I will have two 20 sq ft ones and three 47 sq ft beds.....and a bunch of DWC beds.

[@bikedoc59]

I have large grow beds with high flow rates and the bell siphons were getting stuck. I added breather tubes with a floating cup and it works perfectly. Thanks for the advice.

[@Bigelowbrook]

I just put a bunch of fittings together as close as possible to make the the trap. The distance that the water has to get pushed up through the trap is about the same distance below the growbed's water line the top of the standpipe should be. A few experiments and you can fine-tune the length!

[@Bigelowbrook]

yup! Most of the video is shot....just trying to find the time to put it all together.

[@Bigelowbrook]

1) when you run it to the top, it injects the air directly where the siphon needs to break (where the water will "split" and go down the standpipe and also drop back through the bell). this is the quickest way to get it to stop. If you have it lower, it will just send a lot of bubbles up through the bell. 2) I've had breather tubes in the same bells for a few years and they are perfectly clean. There's enough flow through them that it sucks the bioslime out of them.

[@mhramdani]

I have the same problem...water drains from growbed too slow thus air sucked by breather tube not enough to stop siphon action. your solution is awesome...I will try it on my system!

[@Bigelowbrook]

I like to set it around the height of the top of the stand pipe. This help minimize the amount of suction that it has to do to get the water through the breather tube. If you set it too high, it can sometimes not have enough suction to remove the water from the cup.

[@Mrplace001]

When you get into larger grow beds (ours are 4'x30'), these mechanical solutions get cumbersome. We use simple cycle timers to fill the beds rapidly and then turn the pump off and allow to drain. The nice thing about a cycle timer is you can adjust times between fills, and by adjusting the valve on the drain, can adjust how fast or slow the bed drains.

[@Bigelowbrook]

That's a good cycle time. Mine are about once an hour. I'm happy to hear you're using this style of siphon...a lot of people have told me it's too complicated but I have never had a problem with it...except for the roots. ;-)

[@petri523]

Thanks a lot. Once I added my gravel my siphon would not shut off properly. I added a free floating cup (1/2 inch PVC Cap) and it worked like a charm. In my opinion it sure beats trying to adjust all the other possible variable. Cheers!

[@Bigelowbrook]

Also, I debated adding a couple of little pieces of foam to the top of the cup to keep it upright. I still may try it.

[@Bigelowbrook]

They can be purchased at Home Depot or Lowes in the plumbing department. There's usually a rack of little fittings.

[@Bigelowbrook]

Thanks....I've been using this in my newer system for about 6 months and it has never failed. Even changing the flow rates hasn't phased it.

[@sammer78]

Great idea. I´ll try the next season. My system is very small, but from the beginning I had problems with the sizing of the siphon, and often the problem occurs that the siphon does not cut or start well. I am preparing a video to share what I have achieved, because your job is being a great inspiration for me, but small-scale ...

[@Bigelowbrook]

I've never heard of problems with grow bed sizes. If you have a larger bed, you reduce the amount of space between beds...giving you more root space per square foot. I've seen some big media beds and they run just fine. Maybe people use the smaller beds because it was the only way they could get the siphons to work....?

[@Bigelowbrook]

Yes, I'm familiar with affnan's siphons. I'm fairly sure that the flow rate with this type can be much less his - i'm trying to get my system to use minimal amount of flow to save energy. Regardless, either type would work for most applications.

[@amazonpott6484]

Thanks, after adding pebbles I had the same problem. Applied your solution and works great. For the trap underneath, I used a formed single pipe (3/4) that they sell for condensation exhaust on HVAC units. cheap and good-looking. Once again, thanks.

[@lannyplans]

Best 12 year old video I have seen in a while!

[@putingagta]

this video of your bell siphon design just solved the problem that has been bugging me for days... thanks a lot...

[@Bigelowbrook]

It's used to create a little back pressure inside the bell so it will "burp" as the water level rises.

[@jamascc]

Excellent innovation - I messed with this problem for ages and finally got it by fiddling with the incoming flow-rate - BUT - your enhancement with the cup looks like the answer to the problem of breaking the syphon cleanly. Will try it out on my grow-beds asap. Many thanks :-)

[@jeff-xy7qp]

This is by far the best bell siphon demonstration I've seen on youtube, thanks!

[@mexcar007]

I have found that by either lowering or raising the drain pipe at the bottom of the siphon you can adjust the problem of the siphon getting stuck either at the low position of water or high position.

[@Bigelowbrook]

it's a 6" pipe. Then it's offset from the stand pipe so it all fits in. It could fit in a 4" pipe, but it's a tight squeeze. I like the 6" so I can get my hands down in there.

[@Bigelowbrook]

Some people don't think the trap is necessary whereas I like them. Instead of making it the sideways "S" shape like shown, you can twist the pieces around so it makes a loop and the exit of the pipe is almost the same spot as the drain. Either way, it doesn't take up much space. Just set it up where you can remove the trap and try it both ways! ;-)

[@zohar963]

thanx for the quick response- ill try it with the cup addon soon, let you know how it works out,thanks again...

[@valschep]

Hi! Great modification! Most of my bell siphons work great, but the only problem occuring is indeed the breaking of the siphon when the water flow changes. Thanks! Thumbs up for the inventors.

[@TheLordHumungus]

Genius! I don't have a particularly large bed, but I have had the same issue with the siphon slowing down but not cutting off every time.

[@Bigelowbrook]

I think you meant a 4" media guard. Yes if you make it oval, it will all fit, but It's really nice to use the 6" so you can get your hands down in there.

[@Bigelowbrook]

This siphon should work just fine with it! It's all standard parts you can get at any hardware store too. Just experiment with the standpipe height a bit (don't glue it in!!!) before filling the bed with media.

[@Bigelowbrook]

+1 That seems to be a common problem...people get the siphons working properly then add the media and it stops working. ;-) Glad my little trick helped!

[@Bigelowbrook]

I've used the Affnan siphon and it works fine. I just prefer to use a true bell siphon. I"m willing to wager that this siphon can start with a slower fill rate too. ;-)

[@lfthzmrk]

It definitely works! I had a bell siphon that was not breaking siphon. This one small addition fixed it. My siphon is now trustworthy rather that frustrating. Thankyou!!!!

[@Bigelowbrook]

good point on not being able to turn it. That "feature" sure does come in handy!

[@RyukoKasei]

Especially when aiming for low flow, you should try to use a funnel at the end of the stand pipe, a bigger bell will need to accompany that design likely as well as a bigger strainer and a smaller outlet pipe ( 20mm, 3/4" , but it is down to the inflow of your pump). What are the details for the pumps you use off grid ( my system is off-grid as well and I am using 14l/min // ~2.5 gal/min 12V caravan pumps to pump the water, 1 per two grow beds) ?

[@lannyplans]

An air lock cup on the exit will be necessary if the flow rate is too low for the diameter of the foot tube/ low end. If the flow rate is too low, air bubbles will rise up the foot tube and break the siphon. A cup of water at the exit will prevent air bubbles out of the foot tube. I discovered this using slow flowing in line water filters.

[@Bigelowbrook]

I'm fairly sure I had posted on the BYAP site. As usual, most people bashed it...the few that tried it, loved it. ;-)

[@hughdman]

Excellent! I have been bitten by the Aquaponics bug and I think you just saved me a whole lot of heartache! Thanks so much!

[@hydrillakilla]

Instead of a floating cup, I found that by running the tube through the bell. From there it is routed from the top to the bottom of the stand pipe. (like a pipe inside a pipe) this way the slits on the bottom of the bell break the siphon instead of the breather tube. The physics of the tube are not for to break siphon but rather allow the water level to rise before sealing off air flow to the bell thus increasing the pressure inside the bell and so on. You can adjust the level of water inside the grow bed by changing the length of the tube.

[@Bigelowbrook]

There's a media guard around it. The weight of the PVC keeps it from floating...barely. I do put a small rock on top of it. ;-)

[@DanYHKim2]

This is an excellent modification. I've always had siphon problems because of inconsistent water flow. Your trap and floating cup let the siphon have the 'abrupt' changes of pressure that let it work every time, even when the water input flow is low.

[@marlonchavarria978]

Have you ever looked up water surges? There's plenty of hobbyist that use this to create waves in their fish tanks. The surge is placed above the display tank. In your situation the garden table would act as the surge and it would dump water into your sump. It's much more affordable because it requires half the plumbing and works great every single time.

[@MM-sb1gd]

Brilliant and simple! I'm just now planting my first-ever garden. WHY do you need a siphon in your planter box? Couldn't you just drill dranin holes in the bottom of the planter? Or is this hydroponics? Or What please help?

[@richardfeiller4286]

the best part of aquaponics is in creating a custom application that works for you; it helps justify the $10 tomatoes. :-) there are many different designs that work flawlessly. mine are much simpler and have been up and running for 3yrs. With that being said you have put a lot into your design and you have produced a well explained video, nice job.

[@diyslave5543]

What if you heated up your 6" pipe, and press down on it to make it a bit oval? All the parts for the bell syphone should fit easier?

[@davebean2886]

Thank you for the video. Do you have any idea how big the diameter of the discharge tube can be. I have a situation where I need to empty a tank very quickly and repetitively after it fills up again.

[@firemail1]

Love it bro. been trying for 3 days to get mines going. looked at your video and now i can rest!! Thanks a lot for posting!!

[@samwisdom3213]

Is the trap needed? I wanted to do a direct dump to the sump below my grow bed. In your opinion should I plumb in a trap or would a direct downward discharge work?

[@CMZneu]

Great video! was not getting what the elbow turn thing at the bottom was supposed to do until i saw this video

[@presse55]

I like this design of the bell siphon, particularly the water trap enhancing how quickly the siphon engages. I'd like to build one, and have a question. Are there any guidelines for the lengths of the long arm and short arm of the water trap? I suspect these influence the "high water line", though I'm not sure. Your insight is greatly appreciated. Great channel!

[@DocScience2]

Please use a small diameter cup. If the braker tube is 1/2 inch, then, use a 3/4 inch diameter cup of the same height as the original. It should not wobble as much on the end of the pipe, but still work well. If you have tried it, how well did it work ? Even a 1 inch or slightly larger should work, whatever you can find at first.

[@RyukoKasei]

What size grow beds do you have issues with the bell siphon ? I use 1200mm x 1000mm grow bed sizes with no issues. But I have to say that the Bell siphon design is based on half round bottom inlets for the bell itself, a 4mm drain hole in the stand pipe/bulk fitting and no breather pipe at all. It breaks the siphon all the time with no issues. The half rounds are 18mm radius done with a 36mm hole saw. I like your solution, very creative. :D

[@tonyp4357]

THis is a great solution, justa question. What or how do you keep the cup free when the growbed shale is filled in the bed. Do you have a outer protector that the cup floats in? I did not see a guard at 2.30?

[@HaziqIzzad]

one question. is it necessary to have the u-bend for the drain pipe?

[@Bigelowbrook]

Sorry, It's mostly for air. The nutrients will have no problem getting around in a bed that constantly flooded. In DWC, you usually have to keep bubblers in the water to keep it oxygen rich. In my system, I flood and drain the beds which drain into a DWC. This action provides enough O2 for the DWC so I don't have to waste electricity with any bubblers.

[@ChrisT-zj7ox]

After watching your video, tried the trap at the end of bell siphon. Found that the bell starts floating. How do you stop it from floating or control it to retain the proper water height? thank you Thanks

[@Bigelowbrook]

There's a media guard around it. You can see me putting it in near the end of the video.

[@icovada]

New to this channel... why do you need the grow bed to fill and empty continuously?

[@heckyes]

Where would I get a Bulkhead fitting like that? Did you have to order it? Maybe a plumbing outlet or something?

[@craigbryant9811]

I just started watching your videos so if you covered this in another video I apologize. How often do you flood your system for your plants?

[@Bigelowbrook]

I bought bunch as surplus from ebay, but I think you can order them from McMaster-Carr.

[@Bigelowbrook]

I haven't sized the pump yet since I'm temporary running everything off of our house (which is over 300' away!). Mostly likely I'll get a couple of Iwaki pumps...since I do work for them. ;-)

[@tokejyn]

what keeps the entire bell siphon submerged? is it surrounded/covered by media?

[@rickyready]

Cool, maybe add some string or something to keep the cup loosely in place... to make it easier to install and remove ;-) when that growbed is thick and lush with greenery you may be glad as access is reduced if you need to remove for some reason. Thanks for the great update.

[@chan108dra]

question --how is the cup going to float --as I understand the whole bed is covered with growing medium.

[@cre8tiveweb]

Hey great video. the elbow to the top of the cap that is attached to the clear tube. where did you get that to buy and do you have an online link if it can be purchased online. thanks much

[@rhkennerly]

where do you get a media guard that has space for the cup beside the siphon?

[@Jackthelong]

And can you plz tell me what kind of stone/gravel is that in this video? I need to know I have in plan to build my own aquaponic sistem!

[@stoutmtc]

Thanks! I like the updated video footage - makes the whole thing quite clear. I also like how the P-trap makes the siphon start up so well.

[@ivanloeramty]

Very nice videos please don't stop posting them for beginners like me they are very helpful nice job again and greetings from mexico

[@sandy7m]

USING A TIMER I had the same problem as yourself - the flow rate was about the same as the syphon rate. The trays would fill. Then the bell would kick in and suck the tray down to the point the siphon should have broke. At the end, when the tray level was near drained, the bell would continue to suck air and water and the trays would not start to fill up again for a very long time. Slowing down the flow rate did work but it still took ages for the syphon to break. I did look for answers on KZbin but could not find anything (I obviously did not manage to flag any of your hyperlink words). Back to basics - one way a syphon can stop, is when it runs out of fluid. One way to make sure that happens is to stop the water pump. I timed how long it takes for the trays to fill (just over 10 minutes in my case.) A mechanical plug-in 24 hour timer has 15 minute segments (budget ones have half hour segments). It was a simple decision process deciding to use a timer to control the pump so it would shut off (for a short time) after the beds were full. The pump runs for 15 minutes and in that time the beds have filled and the bell has started syphoning. For the next 15 minutes the pump is off and during that time the trays will have drained and the syphon is broken completely. This means it takes about 20 minutes between the time the syphon is broken until the beds are full again. I have found that the beds stay moist using this cycle. What the long term effects on the beds will be, have yet to be seen (this is my first Aquaponics project). Problems I can see with my method is - * Increasing wear and tear on the pump as it stops and starts. * Loss of moisture in the bed as the weather gets hotter (spring here just now), * Cannot use larger trays for any future additions to the aquaponics system. On the plus side - * Greatly reduced the electricity used by the water pump. I will look at what happens when I have the pump shut down for longer intervals - maybe 30 or 45 minutes. I am aware that biomass needs constant waterflow. However, the microbes and algae will survive up to an hour without any water flow. It is worth noting that my tray system works on a very small scale so I designed a very small bell syphon (with no Break Tube). If the trays do not stay moist enough for the plants I will have to redesign the method for breaking the syphon.

[@justgivemethetruth]

Did you experiment with making the bottom vents larger ... that looks like it might be a problem since it cannot take water in fast enough.

[@GoatLocker1]

Great work. I have battled with bell siphon from day 1. I like what I see here Thanks

[@MarcelLENORMAND]

Very cool. Does the cup have to rise and fall? Surely, if the water is being sucked out of a small fixed cup at a reasonable rate then it would behave in the same way? Also, thinking about the faff of more fittings to get the breather tube into the top of the bell, could you cable-tie the breather tube up the side of the stand pipe then poke it out at the bottom of the bell (where the bottom vents are)? Just musings, not criticisms at all. Keep up the great work and thank you for sharing!

[@Bigelowbrook]

I am trying to get a very low flow rate in the beds so I can run smaller pumps which consume less power. This greenhouse will be off-grid so I need to save as much energy as possible. Pumps are a huge waste!

[@sregev74]

Can you please explain why is it you need 2 siphons? I have seen a great number of systems and it is the first time I saw that....

[@TheChasathome]

Great idea! I will use it and pass it on to anyone else who is interested. Thanks for sharing.

[@stoutmtc]

Hi Rob, Wondering what you consider a "large" growbed? I haven't had this problem, myself.

[@Bigelowbrook]

I suppose that could be the case, but these run perfectly fine as-is.

[@yjfoo23]

Do you dip your plant roots in trichoderman solution before you plant them in aquaponic grow beds?

[@Bigelowbrook]

+yjfoo23 no. I haven't had the need to try it yet.

[@Bigelowbrook]

I played with a longer cup and this is what I found: 1) this is a standard cap that you can get at the hardware store; 2) The drain level is whatever the height of the cap is, so there will always be water in the bottom of the bed...the taller the cap, the more water that sits there; 3) If you leave the gap between the tube and the side of the bell just a hair bigger than the width of the cap, it sort of stays aligned in place. (after I took the video, I fine tuned this part)

[@jfdesignsinc.innovationsid1583]

Dude your really onto something amazing and the potential that can come forth from your idea could be huge.... mainly because its so simple and works if your there or not.... I’ve always thought or wondered about the potential for being able to have fine control of a bell siphon in action.......think about it In society..... (an this is just an off the cuff example.). water tower supplies water to a neighborhood... the tower suddenly is full.. bell siphon starts , neighborhood has water...., now water can be resupplied to tower or not in small or large amounts, anytime ,wont effect the neighborhood whatsoever....., everyone has water until its empty,,,, well it empty’s......no water until it fills again...... suddenly you put In an additional water tower.... now you can supply a neighborhood , garden, desal plant, pigeon farm or whatever. ..with a continuous constant supply of water ,, with no pumps, no power, almost no valves.... and the tower is just an example,,, it could be a water truck parked on a hill,, or a building on a hill, or a tower next to an artisan well or stream..... anyway its just my example of how what your delving into here ,, could be onto something big....email me if you would like to put some pencil to paper an hurl some ideas at one another.! Thanx for upload! [e-mail]

[@frederickjohnh]

A couple of comments on the design. 1) Do you really need the small tube run clear to the top? Could you not run it to the side of the pipe and accomplish the same thing? Air will rise to the top. 2) Could you accomplish the same thing that the cup is doing by drilling a hole (or holes) in the wall of the outer pvc pipe? I would be concerned that the bacterial slime will build up in the clear tubing. Bigger is better when it comes to piping in aquaponics due to slime and sediment buildups.

[@T1ger8oi]

is it possible for the bell siphon to work if the exit tube is above the grow bed? i was wondering if you put 2 bell siphon setup next to each other. when 1 starts to flush, maybe it can flush into the second setup right next to it. then it will continuously flow back and forth. im having trouble understanding how the bell siphon works. or maybe the exit tube can enter the second setup at the bottom of the grow bed. sounds feasible.

[@AmyLuthien]

You could just eliminate the breather tube altogether. I've got a similar setup, but I opted not to add the breather tubes. My bells siphon just fine and are very reliable. The advantages are there are fewer parts to make the bell so you save money there, and there are fewer things to malfunction (breather tubes getting clogged up with debris for instance.) If you search around here on KZbin for Affnan's Aquaponics you can see one in action.

[@joeriscica7328]

Having some trouble on my home system getting siphon to initiate (it air breaks just fine without breather tube). Is the trap you're referring to the bend in the drain pipe? Right now I have a straight pipe going down into reservoir.

[@ahlong9898]

About to attempt my first aquaponics setup and your videos have been my "must-see" prep videos =) I am sure your videos will be saving lots of my future aquaponics nightmares

[@Smalls4068]

Ive been watching all your videos and i have to say that they are some of the best aquaponics,greenhouse videos ive seen. i am very impressed with all the thought and work that you've put in to making your dream greendome. i have an aquaponics greenhouse as well but you give me a lot to think about for my next greenhouse. keep the videos coming. i cant get enough.

[@karachampion]

I have been doing a lot of research to find the best way to build and begin my aquaponics system. This seems to be the best siphon that I have seen. Will DEFINITELY be using this once begin my build!

[@frederickjohnh]

What do you mean by "minimal amount of flow to save energy"? I am trying to understand what you mean or want to accomplish but I am just not getting it.

[@tallyfisher8742]

I am building a much smaller unit with a grow bed 12" x 12" x 34" with a 30 gal fish tank. I was wondering if you could help me determine what size plumbing I should use to build the right bell siphon for my first aquaponic system. Thank you very much, your video was very informative.

[@Bigelowbrook]

You could make a small bell siphon using 1/2" pipe for the bell siphon. I show one in one of my older videos here. kzbin.info/www/bejne/lX-kmod7pp6qa9E

[@ChrisT-zj7ox]

Do you use a weep hole at the base of the stand pipe with the trap? Love your videos, thank you for sharing them with us! Thank you

[@Gamersnewscom]

Thanks for sharing. I may run into this problem when I setup a bigger aquaponics system.

[@kishidabu]

how critical is the height of the of the breather tube where it comes into the bell? Can it just be anywhere above the standpipe level or is its placement more critical?