I have been using just the least expensive grocery store clorox I can find assuming it was all 6% strength. Had the wife pick some up to shock the pool with today and low and behold it said right on the front that it was 2.75%. I have looked on jugs before and have seen nothing that calls out the strength so I thought it was just not required to sate the strength on the jug. Surprised I just assumed all the stuff you get in the grocery store is 6%. That obviously is not the case. My question is what brand should I be looking for to get the 6% strength? What do you all use? Thanks for any help.