building a small bell siphon

[Anne Phillip]

Has anyone built a system with a small diameter bell siphon?  I'm thinking of one with 1/2" or 3/4" stand pipe.

What's your experience with smaller siphons, what issues or adjustments did you make to be successful?

[Cheri Bower]

Hi Anne,
I reacently made one for my sons science project.... I used a standard bulk head fitting and a 1/2 inch PVC for the standing pipe. It did not fit into the fitting, so I heated one end of the pipe and inserted a 1/2 inch socket to expand the pipe end. This worked great! I used a 1 inch pipe for the bell with a one inch cap. I used a 1/4 inch drip irrigation elbow and a piece of aquarium tubing for the snorkel. Then used some screen for the guard.
The whole thing works great.. I used this article to help me. http://www.ctahr.hawaii.edu/oc/freepubs/pdf/BIO-10.pdf

[Cheri Bower]

P.S. It is important that the drain pipes have 2 elbows.

[Jim Fisk]

Only IF the siphon has trouble starting. You might not even need one much less 2. There are so many scenarios that there are no rules set in stone. I include two 90s just in case as I have no idea what a customer's set up actually is and there are an infinite number of possibilities. Use'm if you need'm but don't forget they are there to help it start which by definition makes it harder to stop as well. Simple reaction theory. A straight short tube beneath will stop at first try while a siphon with 2 elbows might take 3 or 4 tries before it stops. But who's counting as long as it starts AND stops.

Some toilets work better than others and they use the same science. Next time you are at Lowes or such check out all the different elbows and bends and sizes of pipes built into the trap or siphon after the bowl and before the "donut". If it were a perfect science they would all look alike but they are far from it and thus all work differently, some better than others as we all know too well. Good news is you can try all sorts of methods with your siphon on the cheap but if you invested hundreds of dollars in a toilet and it doesn't flush well there is nothing you can do to help it but replace it.

Cheri Bower said:

P.S. It is important that the drain pipes have 2 elbows.

[Terry Healy]

I found this .pdf very helpful, although the comments above seem to have some improvements.

http://www.ctahr.hawaii.edu/oc/freepubs/pdf/BIO-10.pdf

[Anne Phillip]

Thanks for the links to the publications Cheri and Terry, and thanks for your experience-based input Jim!

[Jack Dunbar]

Hi Anne. I have a bell syphon made with 1" PVC over a 1/2 drain. I did use a snorkel tube and I did have trouble getting it to work properly until I put a small empty pill bottle at the bottom of the snorkel tube. The pill bottle is held in place with an oring being used as an elastic. My media guard around all this is a 4" PVC with slits cut into it. It's been up and running for a month or so with no problems. I wasn't sure if it would drain fast enough but it will drain my 40 gallon tank (filled w/ media) in just under 3 minutes. I'm guessing that's 15-20 gallons of water. prior to putting the pill bottles under the snorkel tube, it would dribble and not shut off but with the pill bottle, it shuts off very quickly. This was my first attempt at a bell syphon so I'm sure there are others that may work better.Oh, I almost forgot... my stand pipe is approximately10" high and 15" vertical below the bed to get it down close enough to my FT, then an elbow and  then a 7" horizontal pipe and then a 45 on the end. I have 2 grow beds with bell syphons and I turn the 45 in such a way that as they drain into the FT, it helps create a swirl motion in the FT. I hope to post some pics of my setup in the near future. This is a father/son project. my son is 5 and he keeps telling me that  he's gonna go fishing soon. We call this setup "Kennys' Victory Garden". Take care... 

[Anne Phillip]

Thanks Jack! It sounds excellent! I hope you guys can go fishing soon :) Thanks for taking the time to tell me about your setup. It's great to hear about specific arrangements that were effective.

[David Langham]

I just built 2 3/4" PVC syphons for my 2 half barrel grow beds. They have been working great for a week. I used a 1" to 3/4 adapter as my funnel at the top. They are about 10" the high with 16" horizontal and another 6" vertical to the sump. Drains in about a minute.

[Anne Phillip]

Thanks, David! I'm glad to hear they're working great for you!

David Langham said:

I just built 2 3/4" PVC syphons for my 2 half barrel grow beds. They have been working great for a week. I used a 1" to 3/4 adapter as my funnel at the top. They are about 10" the high with 16" horizontal and another 6" vertical to the sump. Drains in about a minute.

[Jim Fisk]

It occurred to me that I have not shown the group our newest bell siphon for a small kitchen garden. In this small size (3-4" media) you run into things like "surface tension" which has next to no effect in the larger sizes. Anyway here are some pics that should be easy to duplicate. I use 1/2" sch 40 thick wall pipe to make the inner diameter as small as possible. The bell is 1 1/4" and the GG is 2". It is adorable if I may say so myself:As always the "O"ring goes underneath the GB as it sets nicely into the groove in the grey electrical threaded adapter.

[Jeff S]

Good job Jim. I set up an "under the bed" type tote, about 36"x18"x6" in my basement using a similar setup. I did have a tuff time getting the right amount of flow so it would start and stop properly but eventually got it. BTW the sides of the tote have to be supported.

[Jim Fisk]

Hey Jeff, yes these little guys are a bit more of a challenge due to surface tension showing it's ugly head. I built this one for a customer and have sold a few now on eBay so I wanted it to be as easy as possible to tune in over as broad a spectrum of water flow as possible. It did take a bit of experimentation and I found the 3" tail that can be swung up and down to be a real asset.

Good advice on supporting the GB tray. Seemed alright during testing but I bet it will fatigue over time but a wood frame nicely stained and sealed should do the trick. I plan to get my set of wire shelves off the storage truck one of these days and plant a kitchen herb garden with some goldfish in the FT. We have the perfect double window in the kitchen. I just worry that the constant sound of running water will keep my wife running as well