Awesome work, excellent info. If your off-side sac had a check-valve in the vent line, I bet the other side fill pump would not draw air. This would reduce your fill time and improve the flow rate. yes, a larger intake setup would improve the numbers as it would offer more flow capacity. Down side is, there is a pretty good price increase when you step up from 1" to 1.25". But, a single 1.25" will be less expensive then a pair of 1"