Backyard Aquaponics
A place to discuss aquaponics

I'm in the process of assembling my aquaponics and draining system. I'm having trouble with my bell siphon. It seems to float instead of staying and the water never seems to get above the standpipe inside the siphon as if the air is preventing it from getting up. Can anyone help me?
Also, is there a specific height the top of the standpipe should be from the top of the siphon?
So far, i'm testing it without the grow media yet.

What do you mean "as if the air is preventing it from getting up"? Do you mean that the air inside the bell is not allowing the water to rise up to the height of the standpipe? If this is the case then you have something preventing the air from escaping into the standpipe such as blockage in your drainage pipe, and then to the drainage pipe. Air should flow freely into the standpipe and water will follow and start the siphon.

As for the floating bell, you may want to tape a rock on the top of the bell just to see if it works. If it floats a bit, shouldn't be so much of a problem, because the siphoning action should suck it back down when the siphoning action starts and it will float again when the siphon breaks.

Try putting a weight on top of the bell.

Some pics of your bell, standpipe and set up would also be helpful.

Is the end of the pipe going directly into the fish tank? Or open to air?

Open air, then falling into fish tank

I think we do need a few photos.

Is the water overflowing into the standpipe?

The siphon troubles (after making sure of a few things like the elbow not facing upwards, even a few mills up will stuff it up), is usually a case of too much water flow, or not enough. Can you up the flow at all?

I have mine doing the same since I connected 2 drains into a T and ends up draining towards just one end.

Try checking the drain pipe on the bottom, if the pipe is angled up the bell will not be able to push the water on bends.

And pics would help.

I had simular problems, when using 40mm bell and 15mm stem pipe, I had the same problem when I went to 50mm bell and 20mm stem pipe, I added 4mm hose to both with caps and still the same problem, I found out that my main problem was that my drainage was too small, I was using 19mm black Polly pipe that fitted to the two bulkheads I got from a constant flow aquaponics shop, I upgraded my drainage to 25mm pipe, and all has worked fine ever since, there is a view of it in my video, I fixed the leak problem by extending the pipe to the 90deg pipes, I didn’t use fittings or glue to keep them in place, that seams to let the air out of the stem pipe easier and creating a good siphon,
I still have the same size bulkheads, just the drainage has changed,

I hope this gives you some ideas on how to fix your problem,

Thank you everyone for your help. The issue was the drainage. My original set up had all the drains with 1" pvc meeting at two T fitting into one pipe and draining into the tank. The tank was originally beside the grow beds. What I did was remove the pvc drains, elevate the grow beds another 8" by adding construction blocks under each stilt, and moved the tank under the grow beds. They now each drain individually into the tank guided by pond tubing. The siphons work perfectly now. Thanks.