Bell Siphon

[Christopher Brickey]

 I have been trying to get this bell siphon to work for a week now. i have 2 2'x3'x9" drain tables and according to this pdf doc.: http://www.ctahr.hawaii.edu/oc/freepubs/pdf/BIO-10.pdf I have the measurements right. It works fine without the media in it, but when I add the gravel the siphon will not break. Any ideas? I am at the end of my rope and have seriously considered taking the saws-all to the entire system.

[Christopher Brickey]

 So... bad news. The siphon stopped working last night. Connie, do u have pics of ur siphon? i tried looking at ur page, but i am still a newb and navigating these pages r confusing for me. i will try lengthening the drain pipe now, i guess. any other ideas?

[Christopher Brickey]

 lengthening the drain pipe did not work. the siphon reacts the same... it works for a few hours and then the siphon won't break.

[Tom OBrien]

It was working for a while, so it sounds like you are close. I was able to play with the inflow rate pretty easily on my setup because I have a ball valve between the pump and the inlet for the bed. If there's a way to do reduce the inlet rate a little that sounds like it would be the the thing to try. I don't get a real clean start and stop with mine, but it works eventually.

[Connie Christians]

I've sent you a friend request. I can forward you a pic of the siphon from US Aquaponics.

Christopher Brickey said:

 So... bad news. The siphon stopped working last night. Connie, do u have pics of ur siphon? i tried looking at ur page, but i am still a newb and navigating these pages r confusing for me. i will try lengthening the drain pipe now, i guess. any other ideas?

[Christopher Brickey]

 Yea I thought I was close too. I have messed with the inflow rate and still not working.

Thomas K OBrien said:

It was working for a while, so it sounds like you are close. I was able to play with the inflow rate pretty easily on my setup because I have a ball valve between the pump and the inlet for the bed. If there's a way to do reduce the inlet rate a little that sounds like it would be the the thing to try. I don't get a real clean start and stop with mine, but it works eventually.

[Christopher Brickey]

 I accepted u. Thanks.

Connie Christians said:

I've sent you a friend request. I can forward you a pic of the siphon from US Aquaponics.

Christopher Brickey said:

 So... bad news. The siphon stopped working last night. Connie, do u have pics of ur siphon? i tried looking at ur page, but i am still a newb and navigating these pages r confusing for me. i will try lengthening the drain pipe now, i guess. any other ideas?

[Christopher Brickey]

 Well I give up. I have tried everything (well almost, I guess) and none of it seems to be working. Now the siphon is not even siphoning, no matter what the flow rate. So I drilled holes in the bottom of the standpipe and I am running the pump on a timer. I did have the timer at 1hr on and 1hr off, but the fish did not seem to be getting enough O2 so I switched to 1hr on 1/2hr off. Any suggestions for the time? The timer only allows 1/2hr increments. I really like this set up a lot better than the despicable siphon, so much easier and cheaper.

[Rob Torcellini]

You can try one of these digital timers if you wanted something on the high-end side:  digital timer

Christopher Brickey said:

 Well I give up. I have tried everything (well almost, I guess) and none of it seems to be working. Now the siphon is not even siphoning, no matter what the flow rate. So I drilled holes in the bottom of the standpipe and I am running the pump on a timer. I did have the timer at 1hr on and 1hr off, but the fish did not seem to be getting enough O2 so I switched to 1hr on 1/2hr off. Any suggestions for the time? The timer only allows 1/2hr increments. I really like this set up a lot better than the despicable siphon, so much easier and cheaper.

[Jon Parr]

There's always that, Christopher.  You're not alone.  Simple ebb and flow design might be best for you.  Pump from the bottom of the GB on a timer, and keep a standpipe at the opposite end.  Pump will fill GB until it overflows down the standpipe, and continue to do so as long as the pump is on.  When the timer switches off, the water drains back thru fill tube and pump.  Upsides: damned reliable, backflow flushes sediment in fill tube and pump, power or pump failure results in empty growbed. Downsides: grit may find it's way to pump, and pumps may not last as long with start and stop.

[Christopher Brickey]

Well, I am having a problem now with not enough O2 in tank, so I guess I am getting another pump.

[rick kennerly]

One thing I've seen to overcome the two failure modes in bell siphons is an intermittent "tipper" regulator.  There's a video here about how a Tipper solves both high flow and low flow failure modes in bell siphons.  

MAE 156b Group 4: The Aquaponics Tipper - YouTube http://bit.ly/xWKzgu

I can imagine a regular grid bed flood system of PVC, but with a riser on the end that feeds a tipper as well.  Might be worth a shot.  

[Rob Nash]

here is a bell siphon how-to by Rob Nash, these cost about $10 to  build. 

i have one that has worked without fail for 2 years now.

http://aquaponicscommunity.com/forum/topics/how-to-build-a-bell-siphon