Pond Boss Forums AERATION Systems questions siphon

I have a 2 acre pond I was wanting to draw down this fall. I was going to set up a 4 inch pvc siphon to draw it down. I want to keep it drawn down till around January. My question is, can I put a shut off valve on the exit end of the pipe to keep the system primed?

I don't see why not as long as the siphon above the water line is water and air tight and it doesn't freeze and crack. The valve has to be below the water level in the pond.

marler, a shut-off valve as close as pratical to the outlet would keep your siphon pipe full and minimize the potential for air infiltration. From experience I can tell you that using 4" S&D pipe will only lift water about 12' before collapsing under the negative pressure, so I would suggest using at least schedule 40 tubing and keeping the pipe sections as straight as possible. As esshup alluded to, make sure your joints are 100% sealed. After gluing, I had some small leaks and used a thick, wide bead of silicone around each joint to get a 100% airtight seal. The smallest pinhole will allow air into the system and kill the siphon or prevent the pipe from staying full all the time. I'd also suggest putting a 45* elbow on the outlet to prevent air from being drawn in from the outlet side as well.

Thanks for all the advice