Here are photos of the swivel valve (loop siphon modified) that I'm trying, reason for using this valve is that I have a few smaller growth beds, needed to be incorporated into my aquaponics system. Being small its a waste to use individual valve and pump on each bed.
Growth bed in a row.., side view of the same.
Above picture show the setup, where all the growth bed link to the valve with a common manifold via a "Tee" joint. You can use 50mm (2") Tee only without the need to use smaller pipe towards the growth bed.
Picture from above the growth bed, this I use water tank adapter with excess threaded part cut off to ensure lower water drainage. If you can use kitchen sink outlet then its a better option.
This outlet need to be screen from growth medium. On this container its already provided, as shown by the black panel, it suppose to cover lower part of the grow bed. On bigger bed, you can try those plastic bathroom interlocking mats, below the gravel.
This is the siphon part, there is a drip, a tiny two milimetre hole on lower end cap. This is to ensure during pump cut off, water will slowly drain out. If you don't need this features just use an elbow joint instead of Tee at this point and only concentrate on that siphon part.
As in picture, there is a reducer this is 50~25mm reducer (2"~11/4") this will cause a better flow out of water. Length of that 50mm pipe from the elbow to reducer need to be adjusted for better result. Final outlet is a 25 mm pipe drilled... this drilled holes is to make water cut off better.
I am still experimenting with this design... there are few things to iron out. Design for my Bell Valve is already done... that valve works without fail... this one I am fine tuning it and trying out various sizes and length.