Okay, I'll try to explain the method that we used for years. First, we would locate the standpipe right where the discharge broke over the backside of the dam. This pipe should incorporate a ball valve in its makeup also. At the top of the standpipe, we had enough pvc fittings to end up with a 1/4" brass, barbed hose fitting.

Our venturi consisted of a cheap engine wash gun .... It consists of a wand with a built in trigger, a fitting to plug an air compressor into, and a suction hose that would normally be placed into a bucket of cleaner, or degreaser:
http://www.amazon.com/Anytime-Tools-CLEANING-SOLVENT-Pressure/dp/B000PCDX34

We would connect the detergent suction hose from the gun to the barbed hose fitting on the standpipe, open the ball valve in the standpipe, plug the end of the discharge pipe that went over the dam, and squeeze the trigger on the wand. It doesn't matter if water gets into the cleaning gun because that's how it's meant to work, unlike the suction pump which may be ruined if it's not shut down in time. (found that out years earlier, before switching to this system)

Using this method, we would spray pond water out of the cleaning wand until the discharge pipe over the backside of the dam filled with water. Then we would close the ball valve in the standpipe, unhook the hose from the barbed fitting, and remove the plug or cap on the discharge pipe...instant siphon, provided the connections are airtight.



"Forget pounds and ounces, I'm figuring displacement!"

If we accept that: MBG(+)FGSF(=)HBG(F1)
And we surmise that: BG(>)HBG(F1) while GSF(<)HBG(F1)
Would it hold true that: HBG(F1)(+)AM500(x)q.d.(=)1.5lbGRWT?
PB answer: It depends.