Hi Heppy. That�s an interesting idea and it definitely makes me think....
I may not be completely wrapping my head around it, but is the larger pipe (4� in your example) that you have drawn around the vent - is that open to the atmosphere somewhere? Seems like it would need to be open to let the water inside raise and lower with the pond. You may have already accounted for this, but if you were to add a small pipe from your 4� pipe to the surface to let air in and out, it just may work.
Last edited by Hogfan; 08/25/18 12:24 AM.
