I live in Wilmington, NC as well. Ollies on College Rd has 12.5% "Pool Shock" for $2.99/gal. Through July 7th, they are having a 15% off everything sale, so ~$2.50/gal. The date on the bottle is 13151, so I believe that's made on the 151st day of 2013, so it may be a bit weaker than 12.5%.