If you are in the DC/North VA/MD area there is a place to buy chlorine in bulk. Its about 15%. I filled up 3 (5 gal each) jugs = 15 gallons for about $30.00. Amato Industries. They have a place in MD and Northern VA.
Great find! That's 1920 oz for $30, or .104oz. I wish they were open Sat/Sun.
Sodium Hypochlorite