Um, John P., I wonder if you skipped a decimal point? Removing .04 percent of 5,500 pounds would result in 2.2 pounds of weight, not 220 lb.
.04%, (0.0004) times 5,500 = 2.2
I see your point, and you are correct about how a small change in concentration can have a significant effect on a reaction. But that pesky math can trip up the best of us.