68% Calcium hypochlorite
68% Available chlorine.
1 pound per 9,000 gallons.
 
​NU-CLO Hit Hard will  keep your swimming pool water clean and crystal clear.  These powerful formulas will eradicate bacteria and other potentially harmful microorganisms from your swimming pool, protecting your swimmers against illnesses and infections. NU-CLO Hit Hard will take your pool water from cloudy to clear by eliminating algae and a wide variety of other contaminants. Hit Hard offers chlorinated shock products which are powerful enough to quickly kill bacteria and algae and yet are safe enough for weekly use.