Im curious as to if any of you have any experience with airlifts and the physics behind using air to create the "venturi" effect that a dredge accomplishes with water. Do you need to be at least at 1 atmosphere (33 ft.) to achieve the desired results or will it work in shallower water? Does the size of the intake pipe make a difference? If the outlet is vented into a trap basket that is submerged, will that be more efficient? Any help in this matter would be greatly appreciated.