TM 10-4320-303-13 2.5.5.3  Determining Hypochlorite Solution Strength . NOTE     Do not confuse the terms "dosage" and "residual."     Dosage refers to amount of chlorine added to the water.     Residual refers to amount of chlorine remaining in the waterafter 10 minutes. a.  Determine desired chlorine dosage or solution strength. b.  Check listing on table 2-19. Read across for required quantity of calcium hypochlorite powder needed. c.  If chlorine requirement is unknown, start with a 1.0 percent solution strength.  Adjust in accordance with chlorine residual tests. NOTE Table 2-19 is based on strength of calcium hypochlorite at 70% strength. Table 2-14.  Hypochlorite Solution Strength Index.' Dosage (ppm) Solution (%) Required Quantity of Calcium Hypochlorite (oz.) 0.25 0.05 0.50 0.50 0.10 1.00 0.75 0.20 2.00 1.00 0.25 2.50 1.50 0.375 3.75 2.00 0.475 4.75 2.50 0.60 6.00 3.00 0.725 7.25 3.50 0.825 8.25 4.00 0.95 9.50 5.00 1.00 10.00 10.00 2.50 25.00 15.00 3.50 35.00 20.00 4.75 47.50 25.00 6.00 60.00 *  Figures in table 2-19 are based on the following: (1)  Model 1955-1:  100 gpm maximum flow rate through unit at 24 spm with 50 percent stroke setting. (2)    Model  A-506131:  100  gpm  maximum  flow  rate  through  unit  at  12  spm  with  100  percent stroke setting. 2-79