Backyard Aquaponics
A place to discuss aquaponics

Hi All,

Trying my hand at a bell siphon, it's refusing to start though. Not sure what the problem is, I'm hoping it'll just require a little tweak.

Below are photo's of my failed attempt! 50mm outer pipe (with cap), 20mm inner pipe, 40 to 20 reducer, 25mm tank fitting. I filled it up to the standpipe, then put the bell on it, then tipped a bucket of water in. It started overflowing, but didn't flush like I was hoping. Then slowed and stopped when it reached the top of the standpipe.




Ideas?

Cheers,

Kenny!

how much fall does it have out the other end???

they need gravity also
i'd suggest min 400mm fall with an elbow on the end with about 50mm of horizontal pipe and another elbow

Like an L with a elbow facing down on the end

It's does cos it doesn't???

when the tank is full, lift the bell suddenly without breaking the airlock. If this doesn't start it, then your inflow is too slow.

However if you get it working with no media, there's a fair chance it will overflow with media added, as there's less volume to fill, the height will change more readily.

Remember a siphon starting is based on the change in water height, not inflow. (if the size of the vessel is constant, then it's inflow, but adding media or using a different GB changes the volume)

Good luck Not starting is because fill is not fast enough. not stopping is because fill is too fast.

bell may be a little short also and maybe not big enough slots in the bottom

This isn't actually for aquaponics So no media will go in there. It's for my feathered friends, I want to flush their water twice a day as ducks and geese are rather messy! I intend to put a float valve up the other end under the level of the stand pipe. Then add a second inlet attached with a sprinkler head with a timer. The idea behind the sprinkler head it to help clean it by spraying the gunk towards the siphon

Bingo, I did what Hamish said and lifted it up a little, and away it went! Then put it back down and it continued to work. So I think the answer is making the cut outs a little bigger down the bottom If that doesn't work I'll increase the size of the bell.

Thanks all!

Kenny, i don't think bigger holes at the bottom will play much part.
What you need, is either a smaller diameter standpipe, or better yet, a restriction on the exit.
Have a look at bell siphon threads, and you'll find photos and diagrams of a couple of elbows on the bottom of the standpipe.
They're designed so you can change the angle to create just the 'right' amount of a lock at the bottom.
This lock means they greater head is required to overpower it, and you'll get a much greater inrush of water when the lock is overcome.
Increasing the size of the bell may help, but I believe that for a given change in height, most dimensions of a siphon have a minimum or maximum size only, not both.
Good luck mate, and keep us posted.

Lifting it up the way I suggested made the siphon act like a pump. You pumped the water higher suddenly, this is why it started, not because there was a greater gap at the bottom.

It looks like its sorted, but if not, how much space is there between the top of the standpipe and the inside wall of the bell? From your pic, it looks like a tight fit. But it's hard to judge from here.

good luck

and ... nice use of a bell siphon!

Have a look at my micro system on youtube... (see link below)
At about the 1 minute mark on the top of the bell syphon there is a bleed hose to assist with shutoff,
what you can't see is a pinhole (Yes, Made with a pin) in the loop of tube above the waterline.
this allows the airpocket to escape through the orifice and the syphon can start reliably.

This has been working now for many years without fault.

ive just made a few same as u have i a 20mil pipe in the bell and i couldnt get the syphon to work so i cut a 20mil long piece of 20mil pipe cut it lenth ways and jamed it in the outlet and away it went

Got a pic? I'm having a hard time visualising where you shoved it

bell

20mil pipe cut and placed it other pipe to help start syphon

Looks a little different to what I have set up? Does your stand pipe just sit in the hole? I had to make mine watertight as it's going to hold water. Still can't figure out where you've shoved that little bit of 20mm into. Is that plastic bag wrapped around it, so confused right now