Backyard Aquaponics
A place to discuss aquaponics

As near as I can tell the differentiating elements are:
1) a funnel to focus the uppermost inlet,
2) a stricture (reduction in standpipe size) below the level of the GB floor, and
3) perhaps a drain trap (U-bend) below that stricture.


Reasoning: all to form more vigorous suction and flow at actuation, preventing equilibrium flow?

Mine is exactly like any other siphon, except for the larger adapter on the top. I use 1" standpipe with a 2" adapter on top of it. No reason for U-bends or anything else. It just causes more water to flow into the opening and letting the siphon start easier.