I have a 6 ich pvc stand pipe or through pipe running through my dam which regulates pool and drains during storms. I am going to siphon my pond and stock it fresh with a different approach due to overstocking by previous owner. My question... Can I attach a rubber pipe clamp reducer (6" to 3") use some elbows and run 3" pvc out into the pond and get a siphon going? I am concerned that after capping and filling the 6" through pipe when I remove the cap that a siphon won't hold up due to the difference in pipe sizes. Will there be too much air in the system?