Backyard Aquaponics
A place to discuss aquaponics

Is the only difference between a bell and affnan siphon that the affnan siphon has an expander at the top of the drain pipe?

Im having issues with my bell syphon stopping and heard that the affnan siphons break the siphon easier.

hey

Ive been running affnan siphons for 4 years in my greenhouse system...

they have performed 100% of the time....

you can see one of my affnan siphon builds here:

http://theaquaponicsgarden.com/siphon_build.htm

jT

I appreciate the response but you didnt answer the question.

Is the only modification the pipe expander at the top of the fill pipe?

Will I need to get anything else at the hardware store besides the expander?

The Affnan "expander" helps with starting the siphon with lower flow. Having a lower flow eases a siphons ability to break.

What would you suggest if the affnan expander does not resolve my issue of the siphon not stopping.

Try reducing the flow (as Jeff mentioned) if the expander doesn't work but leave the expander on since it should help the siphon start over a wider flow range.

In answer to your earlier question about the expander/reducer/adapter - I can't think of anything else you will need but it's been awhile since I made one of these.

I had a problem with my siphon breaking. My grow bed is on a second floor deck draining into a sump tank below. At first my drain line was so long I couldn't get enough air into the line to break the siphon no matter what I did. I added a vent about 4 feet away from the drain and that solved the problem. So if you're still having problems, make sure your drain line isn't too long.

The design of the siphon will not help with the flow not stopping, only with it starting. You have to reduce water flow, like mentioned by others, or check that your drain lines are not tilted up at all. They need a slight down hill flow to them. I have had some drains that where over 20 feet long and never had a issue.

Found the issue.

My drain pipe went down about 12" to a 90 with a small sleeve connected to another 90 that pointed to the sump.

The little sleeve was actually angled upward just slightly. We bent it down and the siphon breaks every time.

Thanks