I recommend everyone do themselves, the environment, and the local economy a favor and use the 5 gallon jugs of 12%. Find it at a local Mom and Pop pool store. The jugs are returnable and when you're working with such high volumes (15 gals. of 12% in the week I opened) concentrating it makes it much easier.

I've still got 36 empty Clorox bottles out in my shed (it's a big shed) from the first time I opened my pool 3 years ago. Anyone need boat mooring buoys?

C.