Ryd...if your BOW is "near" siphon start, then the dam cross over pipe still has air in it. To start your siphon in less than a high water condition, you have to cap off the air vent/siphon break,, plug the outlet, then fill the entire piping system with water, then remove the outlet plug..otherwise, you are still in simple overflow mode.
IF your pipe had some flow through it, you could plug the outlet first, wait a few minutes for overflow to fill the down pipe, then cap the vent tube and remove the outlet plug. IF the down pipe has enough weight in water and the air remaining doesn't create a suction break, the siphon may start.
The elbow at the bottom is only to prevent air from entering from the outlet when actually IN siphon mode already.
Last edited by Rainman; 05/04/13 11:06 AM.
