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

[TCLynx]

Interesting.  Keep sharing those results and observations.

[Chip Pilkington]

Very Interesting Ray...

At first, I couldn’t understand why you were going so big on everything…after you described the system you’re building, it looks like you’ll have a significant amount of water to drain off.

I agree with John – for most backyard applications, the most straight-forward, dependable siphon is the “Affnan” design. It can’t be touched. Affnan’s also gone up and down in size, taking into account size/flow with some of his experiments.

Your application exceeds typical backyard capacities I’d say.

I first built and installed my ”Affnan” siphons and they’ve been flawless. Like you, I love to experiment and “tweek” things. I’m conflicted as in my professional life; I’m always encouraging people to NOT fix things that aren’t broke and to focus on the issues actually needing fixing. That said, the AP system offers wonderful “mental health” opportunities…you know, tough day at work…what can I do here to improve this thing…

In the old days, it was pulling weeds. Today for me, it’s additional farming technologies to create the perfect mini-farm.

Sorry, digressed.

One area I have experimented with on the siphons is the weep hole size. The sizes you are describing are very large. With multiple 3/8 holes, your fill rates are significantly affected I would imagine. The tradition siphon has a flow range which fits comfortably into most needs. I like to hit my desired fill times and have increased weep hole size to allow greater flow into the GB to trigger the siphon (I have a couple of fairly small, quickly filled GB’s I was experimenting with). Once again, my overall system is small (2000L) compared to yours.

My question is how much additional pump/flow will you require to fill, given the large and numerous weep holes? With your volume, will this require the next bigger pump size, as well as watts to drive it?

[Ray Bordelon]

This new design doesn't use any weepholes.  It uses the same drilled cap/bushing that was shown in the videos but without the weepholes. A 25 to 30 watt pump can handle one line of growbeds.  I'll try to do a video in the next couple of days showing how this unit is built. I tried building it with all "off the shelf parts" but I couldn't get it right.  I have a small machine shop...that helps.  Some things may not seem right, but I did the math.  For example, the rule of thumb says use a bell that is twice the size of the siphon standpipe.  I used a 2 inch standpipe with a three inch bell.  If you figure the area of the ID on a 2" schedule 40 and then figure the difference in area between the 2" OD and the 3 " sewer pipe ID they are almost equal.  Well, within a fraction of an inch.  I wouldn't work with a 3" schedule 40 pipe though.

I'l have to give Affnan a look.

Chip Pilkington said:

Very Interesting Ray...

At first, I couldn’t understand why you were going so big on everything…after you described the system you’re building, it looks like you’ll have a significant amount of water to drain off.

I agree with John – for most backyard applications, the most straight-forward, dependable siphon is the “Affnan” design. It can’t be touched. Affnan’s also gone up and down in size, taking into account size/flow with some of his experiments.

Your application exceeds typical backyard capacities I’d say.

I first built and installed my ”Affnan” siphons and they’ve been flawless. Like you, I love to experiment and “tweek” things. I’m conflicted as in my professional life; I’m always encouraging people to NOT fix things that aren’t broke and to focus on the issues actually needing fixing. That said, the AP system offers wonderful “mental health” opportunities…you know, tough day at work…what can I do here to improve this thing…

In the old days, it was pulling weeds. Today for me, it’s additional farming technologies to create the perfect mini-farm.

Sorry, digressed.

One area I have experimented with on the siphons is the weep hole size. The sizes you are describing are very large. With multiple 3/8 holes, your fill rates are significantly affected I would imagine. The tradition siphon has a flow range which fits comfortably into most needs. I like to hit my desired fill times and have increased weep hole size to allow greater flow into the GB to trigger the siphon (I have a couple of fairly small, quickly filled GB’s I was experimenting with). Once again, my overall system is small (2000L) compared to yours.

My question is how much additional pump/flow will you require to fill, given the large and numerous weep holes? With your volume, will this require the next bigger pump size, as well as watts to drive it?

[Chip Pilkington]

Sorry, misunderstood about the weep holes.

I wouldn't stick to the "rule of thumb" on diameters. I use the smallest possible, which freely clears the standpipe. I've also gone smaller on the adaptors and have several GB's without adaptors on the standpipe (see Affnan design on his use of adaptors). I'm seeing that they are not necessary (for me) at my fill rates. The siphon actually engages more quickly without adaptors in side by side testing.

I also use a much thinner wall PVC than SCH40 - it's cheaper and offers more size/clearance possibilities. It's also what happens to be available in Thailand.

Cheers