The vinyl hose you are using isn't re-enforced? The reason I am asking is the bend it makes over the tank would likely cause as much GPH loss as a 90 degree sweeping 3/4" elbows. I haven't tested GPH with the spray bar but I doubt it is much less than with that dual nozzle that comes with the filter. I was looking for better spread and stronger current but keep in mind I have mine running on a smaller tank. I know the current with the spray bar versus the nozzle is so much better it really shows what this filter is capable of doing. I think also what makes the spray bar more effective as far as current is the pressure it creates like putting your finger over a water hose tip. So I imagine that would sacrifice GPH a bit but probably only marginally. I would be interested to either run a GPH test on this myself or if someone else already has I would be interested in seeing the numbers. Cool stuff.
This is what I was thinking.. at least for the intake line where the is suction/vacuum:
http://www.mcmaster.com/#5393K46
to duct tape! big Lol @that.