Went to the local Ace Hardware to inquire about the percentage of their liquid chlorine I got the deer in the headlights look. I went back later to see the owner/manager about the same question and he said it was 15%. As I was walking away he said it was the same as everybody else sold. I know of no pool store in my area that sells 15%. I buy 10-1/2% at Pinch-A-Penny. My guess is that his is 10-1/2% but how would you know? If he is correct and he is selling 15% I have hit the jack pot but then again how do I know? Is there any way to test the percentage?