Its a matter of concentration. The OP was for 2 Tb in 8 oz. That's some pretty strong stuff. To disinfect a well, city water, etc, a concentration of a tiny fraction of that is enough. For years, hikers have used 1 or 2 drops in a quart canteen. It would be a much more popular method if it didn't taste so nasty. I've used 1/4 cup (4 Tb) to kill the algae in a 50 gal stock tank.
