Problems with bell siphon.

[TumblingWheels]

My bell siphon drains normally, I guess, but it doesn't drain all the way down to the end of the air tube. Why doesn't the water level go all the way down to the air tube? And how can I fix it?

[urbanfarmer]

Can you post some pictures?

The bell siphon only fails in a few places; so, if you have a picture or video that would help!

My only guess without more information is that the siphon only drains as fast as the pump fills it when it gets low, and that causes it to never get low enough to "break" the siphon. Try reducing the water coming in and play with that...

[TumblingWheels]

I'll try, but I think I lost my camera cord D:

I can describe it to you, if that'll help XD
1 in. standpipe that is 6 in. high
2 in. bell pipe that is 8 in. high with an air tube that goes down about 5 in. and is sealed onto the cap with silicon sealant
Growbed is 7 in. high
Pump is...I think 30 gallon per hour? I'm not sure, but whatever it was, it was way too much so I split the flow to the growbed and fish tank.


I have slowed the flow down, to the point where it sort of trickles out into the growbed, but the siphon will not drain down low enough.

[stucco]

Does your discharge pipe {the part of standpipe below the bed} point straight down??? My first guess is that you need two back to back 90s with the second one turned up slightly.

[badflash]

Sounds to me like you don't have enough flow to make it kick. The minimum flow for that sort of bell is usually around 1 GPM.

[TumblingWheels]

The discharge pipe goes down but there is a 90 degree elbow going to the left, and another elbow at the end of that pipe.

I tried increasing the flow rate to the GB and the water went down pretty low, but then it wouldn't fill back up.
The funny thing is that if the flow rate to the GB goes down, then the suction rate of the bell siphon also goes down (and the water level never goes down very far, only about an inch under the standpipe, then the GB will start filling up again). The same thing happens if I increase the flow rate, the bell siphon will have a faster suction rate ( water level will go down pretty far, but it won't fill back up). Is that normal?

Another thing though, the standpipe is sort of crooked. It leans to the right a little, so do you think that could be affecting anything?

[urbanfarmer]

Yes. It sounds like the air is not getting in there to break the siphon when it's supposed to. I would remove the 2nd elbow or even try it with no elbows. There should be a tube that is just for the air on the siphon, but if this fails or isn't strong enough I found that air can come in from the bottom as well. Make sure you hear a "gurgle gurgle" sound when the water level gets low and the siphon BREAKS otherwise, it will just keep coming out and never fill up again completely. This is NOT ideal.

[rfeiller]

"Aquaponics 05 - Bell Siphon Troubleshooting [part 1 of 2]" on YOUTUBE. i followed his information have set up three 100 gal grow beds this past weekend. after trying many different methods in the past with constand problems this was the only designed that worked from the get go with following his info for adjustments no problems. no air tube.

i realize there are hundreds of videos on this, but the instructions given in these two videos were the best i have found.
just my two cents

[urbanfarmer]

Yea, the best way to go about it is to just think what is happening inside the tube. Remember air rises and water falls. Take into account the angle of everything. From there, it should be cake to figure out.

[TumblingWheels]

Well, it turns out that the flow wasn't quite at the right flow rate yet. I increased the flow into the GB and now it is working perfectly fine. Thanks for your guy's help