The Smiths have a​ rectangular, above-ground swimming pool. The manufacturer says that the pool holds​ 14,040 gallons of water when filled to capacity. After it is​ filled, Mr. Smith follows the​ manufacturer's recommendation of adding 1 ounce of chlorine for every​ 2,700 gallons of​ water, every other day. About how many pounds of chlorine will Mr. Smith add to the pool in 3​ weeks?