It's just water stains from dirty water. Use On/Off to get the stains out when nothing else works. The stains show the true waterline. Mark it so you can straighten up the paint line later. Bill **************Get trade secrets for amazing burgers. Watch "Cooking with Tyler Florence" on AOL Food. (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)