I am a little slow on the uptake, but if the flow rate is 300 gpm then that would be 18000 gal/hour. That would seem to come out to 0.018 gal = 1/1,000,000 of 18,000 gal. If the desire dose was 40 ppm, then that would require 40 x 0.018 gal/hr or 0.72 gal / hr cl2. If the sodium hypochlorite...