Local janitorial supply store - 55 gal drum of 12% for $150

[waterbear]

IF the pool stores in your area sell 10 or 12.5% chlorine in refillable carboys that is often the best deal, better than bleach much of the time. Check the prices. For example, we sell a 2.5 gallon carboy for $3.99 with a one time purchase price on the carboy of $5.99. After that every refill is $3.99. That is the equivalent of 5 gallons of ultra bleach, which costs more than $4! (Plus you don't have empty jugs to throw away.)