Auto Siphon Technology

[Ray Bordelon]

Hi Aquaponics Enthusiasts,

AP is awesome. The food is plentiful and healthful. The process is interesting. We are all working toward having a smaller footprint. But, the auto siphon is ubercool. I love the mechanics of it all. Maybe it's a guy thing, I don't know. I could watch that thing all day long.

The one component that really makes it fun can also be limiting and at times troubling. There are many people that have systems that operate flawlessly and seldom need adjustment. Yet, I believe that lots of improvements in the auto siphon can be made.

When I decided to try to improve the current designs available, I first had to identify what I saw as shortcomings. The first thing that I wanted to do was create a design that saved energy. Then I saw dependability as the next issue. I needed to increase the auto siphons ability to handle a large variation of flow rates. I also knew it had to be simple without adding any moving parts that can wear and be a maintenance issue.

Currently, it seems as though flow rates are adjusted to the needs of the siphon when flow rates should be adjusted to the needs of the fish and plants. One might say that if a siphon is sized properly, the needs of the fish and plants are met. But, the needs of the plants and fish change all the time. For example, if its a cool damp month you should be able to let the grow beds cycle a couple of times a day without concern for the auto siphon operating properly. Or, if your fish are just fingerlings, they don't need the water flow that mature fish need. People tend to oversize their pumps just to make sure that all of their siphons work. This is especially true for CHOP, CHOP2 systems. If you had efficient siphons, you could downsize your pump and save energy. I don't have lots of experience in AP but, it seems like many people have more flow in their growbeds than is necessary just because their siphons need it. I also believe that faster drain is not only beneficial for oxygenating the plant roots but it saves energy. In a system that uses a continuous run pump, the pump is trying to fill the grow bed while the siphon is trying to empty the growbed. If the growbed is emptied rapidly, that is less time the the pump is being counterproductive and this also saves energy.

I love simplicity. The current designs that only have one moving part (the pump) are pure genius. The more components that a system has, the more problems a system has. So I knew that whatever I came up with, I had to keep it simple. But, simple is not always dependable. The current designs don't have much tolerance for variation in flow rates. This can make them unreliable. If a system gets dirty and flowrates change a little this can stop the proper operation of an AP system. I knew that I had to have an auto siphon that would work regardless of the flow rate.

After giving it a little though, I came up with what I think is the solution. I call it the "No Worries Siphon"...NWS for short. This weekend I built three prototypes of the NWS. They seem to work flawlessly. Of course, I only ran them for two days and nights but, I can't imagine what could be a problem down the road. Please feel free to use this design. In fact, I would be honored if the NWS is used to improve the efficiency and dependability of AP systems around the world.

 The first video that I am presenting is showing a 2 inch "U" siphon mounted externally that is started with a flow rate of 1 to 2 gallons/hour. I like the externally mounted siphon because it saves space in the growbeds, it can be mounted remotely and it can drain the growbed completely, using vertical GB space more efficiently. I tried smaller ones and they worked perfectly. So, I was encouraged to make a big one. The way this siphon worked, I am sure it would work the same with any size, including 6" or larger.  http://youtu.be/mzW6LPJ6urk

 The second video that I posted shows the detail of how it works. It's so simple. I hope you like it.

http://youtu.be/lhBkOTeNKD0

The third video shows it working with a 1" bell siphon remotely located. I imagine that a line of growbeds could all be connected to a common drain manifold leading to a sump. Draining into the sump would be one siphon for the entire line of growbeds. That siphon may need to be 6 inches in a commercial operation but this video shows that it would work.

 To be Posted

[Ray Bordelon]

I am still trying to find a venturi assisted siphon.  Let's not our imagination get in the way of the advancement of AP.

RupertofOZ said:

Ray Bordelon said:

FWIW, I posted a 3rd video:  http://youtu.be/Fpu0MiCwa70

 

Still basically a loop siphon.. just with an extended pipe... here's a video of external "bell siphons"...

http://www.youtube.com/watch?v=Zb2UM8wOzso

 

And one of the Hawaiin aquaponicists... Glen??... uses a single external bell siphon to drain all his grow beds...

Not "knocking" your brainstorming, or your enthusiasm Ray... but it's all been done before... with a 100 variations...

[RupertofOZ]

So you want to siphon the water out of the grow bed faster Ray... fine..

Perhaps look at "jet siphons"... often used in fire fighting systems... basically a water injection into the siphon that breaks the vacuum... and or a constricting "venturi:... which speeds up the flow...

 

But why??? ... most siphons, especially bell siphons... are pretty fast as is..

[TCLynx]

Ray, the venturi assist I think I've seen some one do something almost similar in the past but not the same and not for the same purpose so I think you can claim some originality there.

However, I'm curious if the venturi has much effect on the siphon breaking.  Since you have been concentrating on slow trickle inflow rates it seems you haven't shown us anything on how your modifications affect the upper end of the flow rate range.  I've found that once the trap is added to the bottom of the siphon drain pipe that it usually makes it more difficult for the siphon to get a good gulp of air and that is what usually causes the need for a breather tube to help the siphon break properly and with your venturi action it seems that it might be even more difficult for the siphon to break at the higher inflow rates. 

Got any videos showing the siphon working at the higher flow rates that would normally be needed to kick off the unmodified version of that size siphon?  Then add your modifications on to show it still working at that flow rate with the modifications?  That is what would be need to show that it really does make the siphon work under a wider range of flow rates.  If your modifications mean that the siphon will only shut off at the normal higher flow rates if you do yet more modifications it doesn't really qualify as "no worries", it will really just be a large size siphon that works at a trickle and well a FLOUT will do the same thing.

[Ray Bordelon]

Originality is not an issue at all.  My only concern is that I am burdening the AP community with redundant info.

It could be more difficult.  That is why it helps to upsize the siphon.  I have done tests at higher flow rates and with a larger siphon the sipon breaking gulp happens much more easily.  Again the proper size of the weep hole is important.

Breather tubes definitely are important and at very high flow rates the breather should probably be upsized as well.  This I don't know and it would take some experimenting to find out.

The demos have been disassembled.  Maybe I could do another video next weekend. 

 

TCLynx said:

Ray, the venturi assist I think I've seen some one do something almost similar in the past but not the same and not for the same purpose so I think you can claim some originality there.

However, I'm curious if the venturi has much effect on the siphon breaking.  Since you have been concentrating on slow trickle inflow rates it seems you haven't shown us anything on how your modifications affect the upper end of the flow rate range.  I've found that once the trap is added to the bottom of the siphon drain pipe that it usually makes it more difficult for the siphon to get a good gulp of air and that is what usually causes the need for a breather tube to help the siphon break properly and with your venturi action it seems that it might be even more difficult for the siphon to break at the higher inflow rates. 

Got any videos showing the siphon working at the higher flow rates that would normally be needed to kick off the unmodified version of that size siphon?  Then add your modifications on to show it still working at that flow rate with the modifications?  That is what would be need to show that it really does make the siphon work under a wider range of flow rates.  If your modifications mean that the siphon will only shut off at the normal higher flow rates if you do yet more modifications it doesn't really qualify as "no worries", it will really just be a large size siphon that works at a trickle and well a FLOUT will do the same thing.

[Ray Bordelon]

I need one of those.  Just in case my GB's catch on fire.

RupertofOZ said:

So you want to siphon the water out of the grow bed faster Ray... fine..

Perhaps look at "jet siphons"... often used in fire fighting systems... basically a water injection into the siphon that breaks the vacuum... and or a constricting "venturi:... which speeds up the flow...

 

But why??? ... most siphons, especially bell siphons... are pretty fast as is..

[TCLynx]

Yep to make it No worries you probably should set up again next weekend and show some videos at the higher flows and demo how different size weep holes and breathers would need to be implemented to handle the different flow rates.  See having to do mods every time you adjust your flow rates probably makes it a bit less of a "no worries" type install.

The FLOUT might take up a bit more space though it could be easily done remotly, it doesn't require modifications to operate over pretty much the full range of flows that the drain piping can handle under gravity flow provided the outlet is lower than the Flout itself and is the same size and free draining.

[Cory Cramer]

Ray, I think this could be very useful for someone who needs to use a low flow rate, for example, in an off-grid system where energy usage is at a premium. Thanks for posting.You never know what application someone else is working on, this could be just what they need. I don't think you should worry about burdening anyone with redundant info.

I'm not familiar with a FLOUT, TC. I'll have to look that one up.

[Ray Bordelon]

Thanks, for asking the right questions.  You got my curiosity up and I made time to quickly put together a test...no video though.

I set up the 2" U-siphon with 100% of the flow from a 24 watt 350 gph pump @ 2-2.5 ft. of head.  I drilled four 3/8" weep holes and a venturi was completely unnecessary.  Without the cap on the downpipe the siphon wouldn't go.  I found the cap to be a very good way to start a siphon.  It seems that the holes around the perimeter of the bushing allow the air that is mixed with the falling water to escape easily.  Since, the hole point up.

The siphon broke easily with the end of the former venturi hose submerged in the GB.  I think that is also due to fast drain with a 2" siphon.  I kinda sounds like a toilet. 

It seems as though the only value in the techniques in the videos is for someone that wants a slow fill/fast drain setup.

However, I do believe that the cap is useful.

TCLynx said:

Yep to make it No worries you probably should set up again next weekend and show some videos at the higher flows and demo how different size weep holes and breathers would need to be implemented to handle the different flow rates.  See having to do mods every time you adjust your flow rates probably makes it a bit less of a "no worries" type install.

The FLOUT might take up a bit more space though it could be easily done remotly, it doesn't require modifications to operate over pretty much the full range of flows that the drain piping can handle under gravity flow provided the outlet is lower than the Flout itself and is the same size and free draining.

[Ray Bordelon]

Cory, That is what I am hoping. I plan to be off grid in the near future.  One of my  jobs is that of an electrician and licensed PV solar installer.

Cory Cramer said:

Ray, I think this could be very useful for someone who needs to use a low flow rate, for example, in an off-grid system where energy usage is at a premium. Thanks for posting.You never know what application someone else is working on, this could be just what they need. I don't think you should worry about burdening anyone with redundant info.

I'm not familiar with a FLOUT, TC. I'll have to look that one up.

[TCLynx]

Let me see if I can find some links or the FLOUT.

new-product-flout

of course there is my web site.

Now I wasn't trying to drain a grow bed using the FLOUT but here is a blog post about something I tried that didn't quite work

Pumperflouternating

and a flout video

If you want to connect your grow beds together and drain them all at once quickly, the flout can do it.  Flow rates from almost nothing up to what the pipe can move by gravity all work with no special modifications or changes or caps or holes or breather tubes.

Only drawback to FLOUTs is they do require a little space to operate, otherwise they are really trouble free.

for replacing siphons on multiple beds, I would install the FLOUT chamber a bit deeper than the beds since the Flout doesn't drain the bottom few inches of water from the chamber.

[Japan Aquaponics - アクアポニックス 日本]

Hi Ray,

Thank you for sharing this idea... I love seeing videos like this... if we don't stop experimenting then we will stand still and get left behind.  I think that for some setups this would be good and would be a helpful modification.  Cheers Ray.

[Ray Bordelon]

Hi All,

I wanted to give an update on the R and D.  

I currently have a AP system that consists of an 1800 gal. indoor, inground FT/pond.  In my yard I am building 24' rows of GB's as the time and energy allows.  My next row of GB's will be 3 - 30" x 96" x 13".  The overall length will be 24' and they will share a drain manifold and be controlled by one auto-siphon in by the FT. I want the Siphon to be able to handle a wide range of GB feed rates. The total capacity of the GB's will be 450 gals.  If I use the 40% number for the water quantity after the media is added, then they should contain about 180 gallons of water.  Most of the time I guess the feed rate to the GB's should be around 300-350 gal/hr. I figure a 2" siphon should drain the GB's in about 12-14 minutes or about 1"/ minute.  Does anybody think that might be too fast?

I have now completed what I think is going to be the final version of the Auto siphon.  I had an incident that got me rethinking my original prototype/mockup.  Everybody knows that I am fascinated by venturi's.  Well, I was hanging out in the kitchen and I spotted something called a wine aerator.  It's a very cool looking acrylic venturi that works wonderfully and very low pressure.  My wife got mad at me when I poured my coffee through it in an effort to make a cappachino.  I didn't work but just between you and me it puts a great head on beer.

Anyway, I examined, measured and otherwise scrutinized it...then I made one for me that I could do whatever I wanted with it. So I made this with it:  I works very well but it's not what I was expecting.  The venturi is cool.  It kinda sounds like a little motor boat.  It doesn't create a lot of vacuum to help start the siphon at very low flow rates.  The siphon does start at about 60 g/min which is good for my app.  At that rate, my GB's would have about a 3 hour cycle for those cold nights.  Without the venturi, I would need a higher flow rate to start the siphon but only marginally higher.  The thing that happened unexpectedly was that the siphon breaks cleanly at any flow.  When the water level in the 4" pipe reaches the top, the venturi starts working.  It pulls a small vacuum on the top of the bell.  The air in the venturi tube flows toward the venturi at this time.  When the siphon gets started and the water level in the 4"pipe drops the venturi stops working and it then allows the air in the tube to flow the other way.  When the siphon stops, this air line equals the pressure and the siphon is completely and permanently stopped, until the next cycle.  I have siphon break holes in the bell but they are very unreliable.  It seems that in this situation, with a very long 2" pipe feeding the siphon, when the siphon breaks, a slug of water comes back with a rebound or a hammer effect and starts the siphon all over again or puts it into a state of equalibrium.  I tested it up to a feed rate of about 1000g/hr.  It was almost more than the 2" pipes could carry and the siphon broke cleanly each and every time.