Help! We have 3 toilets in our home, the two on the main level occassionally fill with gray to blackish water that leaves an oily residue--it can take as many as 6 flushes to get the water to fill clear. 2nd floor bathroom never has this problem. None of our sinks/dishwasher or clothes washer has this problem. We have our own well, copper pipes, our home was built in 1994 and we use propane gas for heat. Also, our tub in the master bath often has black specks coming from the hot water side that will cover the bottom of the tub..sometimes running the water for a long time will lessen that but not always. Again, upstairs bath does not have this problem. One plumber we called to resolve problems replaced our bladder tank but that made no difference.