H/T Nuke::
http://www.thefoodguys.com/howtoclorox.htmHow to Make Chlorine Bleach from Pool Shock
Straight off the EPA site...
We bought a 5 lb. bottle of "Shock" from Walmart for $10.97, you can find it in the pool chemical section. Make sure that it is the "Calcium Hypochlorite" not the "Sodium". MAKE SURE IT HAS NO OTHER ADDITIVES!!!!!!!!!!!
This 5 lb. bottle makes 640 gallons of "stock chlorine" (eliminates purchasing 640 gallons of bleach). Each of these 640 gallons of stock chlorine disinfects 200 gallons of water. For a total of 128,000 gallons of clean drinking water for the cost of one bottle of "Shock". And think of the space it'll save.
Directions are at
http://www.epa.gov/ogwdw000/faq/emerg.html or as follows:
GRANULAR CALCIUM HYPOCHLORITE.