lassig, thanks for the drawings. That is very useful. I just made a siphon for my 3/4 acre pond out of 3 inch to lower it about 2 ft. I figure a ft. a day. I will place one permanently thru the dam when they come to fix the back side of the dam. We had 6 inches over 3 days, followed by 5 inches in a few hrs. and that caused the overflow. Eddie, as far as size of pipe vs. volume; assuming same length of suction side, the volume is proportional to the square of the radius.

12 inch 6x6=36
6 inch 3x3=9
4 inch 2x2=4
2 inch 1x1=1
1 inch 1/2x1/2=1/4

so 12 inch carries 4x volume than 6 inch
4 inch carries 4x volume than 2 inch
2 inch carries 4x volume than 1 inch.

probably useless info, but someone may can use it.

Last edited by burgermeister; 04/05/09 09:11 PM.