Backyard Aquaponics
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So, this is a new problem for me:

I have an auto syphon that has a 3/4 inch pvc with a 3/4 to 1.5 in reduser on top for the stand pipe. I have a 3 in pvc to go over the stamp pipe. This has all the necessary holes at the bottom and an air tube to break the syphon.
The problem is that is does not initiate the syphon. It surpasses the water levEl and overflows the bed. When I take a look at the syphon, there seems to be air in the top, between the standpipe and the outer pvc that sits over it, that is actually blocking the water from going in the standpipe.
It is worth noting that I have a kind of sink trap setting coming from the standpipe on the underside of the grow bed. I did this because the regular sraight drain pipeople wasn't working either.
Question: what am I doing wrong and how do I fix this?

Some pictures of your siphon may help us help you.

Your problem (or one of) is too many widgets and attachments... The best siphon design is the simplest design. They do not need inverted reducers atop the standpipe, or breather tubes, or 'S' traps etc.

I would hazard a guess that the trap you've made is stopping air from exiting the bell. For the siphon to initiate, air must be able to be sucked from the bell, down through the standpipe with the water flow. At the other end of the cycle, air needs to be able to get back up into the bell to shut the siphon off.

The original reason for your siphon not initiating (before adding all the widgets) was most likely something as simple as incorrect water flow, it nearly always is... Siphons have an operating window when it comes to water flow... Too slow and the siphon won't start, too fast and the siphon won't stop.

See the siphon design below... Simple = works.

It would take a resonable amount of water to get a syphon like you've described started.

If you have more than one bed then divert some of the flow from the other beds into the troublesome bed to see if it kicks off

Thanks you. I'll remove that bastard trap and try simple. Less is more, right?

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