I live in an area without a pool store. I've been looking for a more concentrated bleach than the 6% at Walmart so I called around & found a pool supply store about 40 mins away who said the percentage of sodium hypochlorite is 20-22% - is that even possible (I've never heard such a high percentage). I asked him a couple of times just to make sure we were understanding each other & he assures me it's correct. With gas prices the way they are right now I don't want to make a wasted trip. He quoted me $12.98 for a 4 gallon case which is way cheaper than anything else I've found. Am I right to be skeptical or did I stumble upon a liquid chlorine gold mine!?