I like controlled experiments like that. I'm also one of those people who just want to know ... like the fact that the spraybar reduces flow by 4 GPH, that's interesting to me.
I just want to be sure I understood correctly: You have the canister on the floor and the surface of the water is 4-feet from the floor level? It would seem to me that height (I believe they call it "head", right?) is a crucial parameter. I would think tubing diameter would be critical. I seem to remember from when I took fluid dynamics that fittings like elbows and tees reduce the flow.
All interesting stuff, nice work.