Chawkphil, did they recommend check valves for the bags at all? Are you draining via the thruhull or above the waterline? Were you tying in the center and IBS? I'm getting ready to order all mine up and when I inquired about what all I might need they gave me a list with only the pump upgrade and 6 other connectors for the sumo bags. I was wanting to drain above the waterline so I had a visual indicator of when they were done and I think that involved check valves between the thruhull and pump or pump and bag? Can't remember which but curious as to what they've set you up with.